Class 3 - Term 2 - PRIME YEARS

1. When 0 is divided by a number, the quotient is _______ 2. 1225 10, Quotient =  ________ 3. 7246  = 1 4. If 70 bricks are arranged in 5 rows, number of bricks in each row is ____________________ 5. A bundle of 2500 rupees is made of 100 rupee notes. How many notes are there? 6. The division statement for the given figure is _________ 7. For 1285 100, the remainder is  __________ 0 1 2 3 4 5 6 7 8 9 10 11 1213 1. 168 wheels are to be put on tricycles. How many tricycles are there? 2. 150 kg rice is to be put in bags that can hold 8 kg each. How many bags are required to pack the entire rice? (The question is \"Tricky\") 51

1. Find dividend, if quotient = 6, divisor = 8 2. Find dividend, if quotient = 4, divisor = 9, remainder = 2 3. Find dividend, if quotient = 5, divisor = 7, remainder = 3 We can check whether a division is correct using the division relationship. For example, for 15 4,  Divisor = 4, Quotient = 3, Remainder = 3 Divisor x quotient + remainder = 4 x 3 + 3 = 12 + = 15 15 is the given dividend. Therefore, the division is correct. 15 - 12 3 3 4 Do the division and verify whether it is correct: 1. 25 6 2. 18 4 3. 38 5 4. 46 3     Easy division Division by 10, 100, 1000, etc. When a number is divided by 10, the digit in the unit’s place is the remainder, and the rest of the number is the quotient. When a number is divided by 100, units and tens digits form the remainder, while the rest is quotient. Examples: 4125 10  Quotient = 412; Remainder = 5 4125 100  Quotient = 41, Remainder = 25 4125 1000  Quotient = 4, Remainder = 125 52 Independent Independent

1. Find the quotient and remainder for the following: a. 75 10  b. 408 100  c. 135 10  d. 5254 10  e. 6025 100  f. 7182 1000  2. Do the following divisions and check whether they are correct using the division relationship: a. 72 3  b. 112 8  c. 98 4  d. 325 3  e. 462 3  f. 325 5  3. By looking at the digits below, guess the quotient. Do the division and check whether your estimation is correct. a. 82 10  b. 325 3  c. 128 4  d. 72 3  e. 1250 4  53

Study the pattern given. 1. Count the number of tiles. Frame the multiplication and division facts for the number of tiles. 2. Arrange 24 seeds in different rectangles. Write the multiplication and division facts for each arrangement. 92 4 40 5 52 2 112 4 72 3 321 3 96 6 75 5 26 28 23 15 16 24 107 8 4. Match the following problems in box 1 to their answers in box 2. Box-1 54 Box-2

Introduction to fractions 55 1 2 1 2 1 4 1 4 1 4 3 4 1 3 A part of a whole is called a fraction. Let’s see a few experiments about fractions. Exp.: 1 a. Take a square paper. Fold it along the middle into 2 equal parts. Shade one part with a colour pencil. We can say that one out of two parts of the paper is shaded, i.e., is shaded. It is half of the given paper. Half = b. Take another paper. Fold the paper into half and fold it again. Open the folded paper. The paper is now divided into 4 equal parts. Shade one part of the paper. Now, one out of four parts is shaded, i.e., part is shaded. We can also say that the shaded part is half of half. It is called a quarter. Quarter = c. Cut off one of the four parts of the paper with a pair of scissors. Now, we have 3 quarters remaining. Whole – one quarter = 3 quarters. Or 1 – = d. Take another paper. Fold it into 3 equal parts. Shade 1 part. The shaded part is one-third, or 1 out of 3. One-third = Exp.: 2. a. 24 seeds are given. Sit in groups. Spread out the given seeds. Count them. Divide them into half, one-fourth, and three-fourth. Count the number in each fraction and write it down.

b. Spread them out again. Divide them into 3 equal parts. c. Similarly, divide them into 4 equal parts, 6 equal parts, etc. = _____ seeds; = _____ seeds; = _____ seeds; = _____ seeds; = _____ seeds; =_____ seeds; Value of fraction Exp.3: a. Take a strip of paper. Fold it into two equal parts. Shade one part. Take another strip of paper of the same size. Fold it into 4 equal parts. Shade one part. Take another strip of the same size. Fold it into 8 equal parts. Shade one part. 1/2 1/4 1/8 Similarly, keep taking different strips of paper and keep increasing the divided parts by increasing the number of folds. Out of all the shaded areas, which shaded area is the largest? In other words, which fraction is the largest, and which one is the smallest? You will notice that though the numerator remains the same, the value of the fraction decreases as the denominator increases. > > > . . . . 56 1 2 1 4 3 4 1 3 2 3 1 6 1 2 1 4 1 8 1 16

b. Take 3 identical strips of paper. Fold each into 4 equal parts. Shade one part in the first, 2 parts in the second, and 3 parts in the 3 . rd You will find that if denominators are the same, the value of the fraction increases as the numerator increases. < < 1. Pick out the like fractions from the following: 2. Write the shaded part as a fraction. 57 Like fractions In any fraction, there is a numerator and a denominator. In , 1 is the numerator; 2 is the denominator. Fractions with the same denominator are called like fractions. For example, ¼, ¾ are like fractions. Similarly, are like fractions. are also like fractions. 1 4 2 4 3 4 is half = 2 4 1 2 , 4 12 12 12 5 , 7 , 1 8 2 8 , , 3 8 4 8 , 5 8 , 1 7 3 4 , , 1 5 1 6 , 3 7 , 2 5 1/4 3/4 2/4 1 2

3. Write the following fractions in ascending order: Equivalent fractions Exp. 4: Take 3 identical strips of paper. Fold one into 2 equal parts, the second into 4 equal parts, and the third into 8 equal parts. Shade one part of the first. Shade 2 parts in the second. Shade 4 parts in the third. What do you see in the shaded parts in the three strips? Are they not equal? To get an equivalent fraction, multiply the numerator and denominator by the same number. 1 x 2 2 x 2 = 2 4 1 x 2 2 x 4 = 4 8 1 x 4 58 1/8 1/2 1/4 , 3 5 1 5 , , 4 5 2 5 a. , 3 7 1 7 , , 5 7 6 7 c. , 1 3 1 2 , , 1 4 1 6 b. , 1 7 4. Circle the largest fraction in the following groups: , 1 4 3 4 a. , 1 8 5 8 , 3 8 c. , 3 5 4 5 , 1 5 b. We can write = = These fractions are called equivalent fractions. Another example: 1/3, 3/9, 4/12, 5/15 1 x 3 3 x 3 = 3 9 1 x 4 3 x 4 = 4 12 1 x 5 3 x 5 = 5 15 1 2 2 4 4 8 ; ; ;

1. Find 3 equivalent fractions of 2. Find 4 equivalent fractions of 3. Find whether the following are equivalent fractions (Tick them) 1. Find 4 equivalent fractions for 2. Pick out the equivalent fractions from the collections: 1. Which of the following are like fractions? Tick them. 59 Guided Independent 2. Which of the following are equivalent fractions? Tick them. 1 4 1 2 a. , , 1 3 2 4 2 5 b. , , 2 6 1 5 2 5 c. , , 3 5 1 5 10 15 1 d. , , 1 2 3 4 3 a. , 3 10 3 1 b. , 1 5 20 4 c. , 1 3 3 8 d. , , 1 4 2 4 a. , 2 3 10 15 c. , 3 5 6 10 b. , 5 3 6 15 d. , 2 7 10 14 e. 2 3 a. 5 11 c. 3 5 b. 6 13 d. 1 2 , 2 3 , 1 4 , 5 6 , 6 9 , 8 32 , 25 30 100 , 50 1 4 1 5

3. If = , the missing number is a. 6 b. 5 c. 12 d. 15 4. In the given figure, the shaded part is 5. is the equivalent fraction for 1 4 2 4 + Addition of like fractions 2 4 1 4 2 4 + 3 4 = 1 4 2 4 1 4 + 2 4 1 4 1 8 a. b. 1 3 1 6 c. d. 4 16 4 12 a. b. 1 2 1 4 c. d. 16 32 30 2 5 60 Exp.: 5 Each student needs identical pieces cut out from transparent sheets (Thick polythene sheets). 1. Addition of One sheet is divided into 4 equal parts, with one part is shaded. This is ¼. Another sheet is divided into 4 equal parts, with two parts shaded. This is Keep one over the other. How many shaded parts out of 4 equal parts do you see now? You will see that you now have 3 shaded parts out of 4 equal parts. Thus,

2. Use transparency sheets to find To add like fractions, we add the numerator, keeping denominator the same. 1 2 1 2 + = 2. 1 5 3 5 + = 1. 1 7 3 7 + = 2+1+3 7 2 7 + 6 7 = 1 5 3 5 + = 1+3 5 4 5 = Add the following. 5 12 3 12 + = 1 12 + 4 9 1 9 + = 2 9 + 1. 2. 1 5 2 5 + 3. = Subtraction of like fractions Just like in the case of addition, in subtraction of like fractions, numerators are subtracted while denominator is kept the same. For Example, 1 4 3 4 - = 3 - 1 4 = 2 4 1 5 4 5 - = 4 - 1 5 = 3 5 61 Independent

Fractions on number line Fraction is a part of a whole. Let us see how we can represent a fraction on the number line. Mark the length 0 to 1 on the number line. Divide it into 3 equal parts. Each part is 1/3. 1 12 5 12 - = 3 13 8 13 - = 1. 2. 4 15 7 15 - = 4 15 9 15 - = 3. 4. Represent the given fractions on the number line 1 3 0 2 3 1 A B C D For example, 1 3 AB = 1 3 AC = 2 3 AD = = 1 3 3 1. 1 3 2. 3 7 3. 3 4 Represent the following fractions on the number line 1. 3 7 2. 5 8 3. 3 5 62 Guided Independent Independent

1. Write the addition fact shown below on the number line. 2. Find the sum of 3. Find 3 equivalent fractions for 4. Put or > < between fractions: 5. Arrange in ascending order: 6. Arrange in descending order. 7. Circle 1/4 of the collection. 1 6 2 6 3 6 4 6 5 6 0 63 1 + 2 15 + 1 15 7 15 2 3 2 15 1 15 , a. 8 12 1 12 , b. 2 7 5 7 c. 1 8 3 8 , 5 8 2 8 , , 1 2 1 8 , 1 12 1 5 , , 1 10 , 8. Find the difference - 2 5 b. 1 5 3 4 a. - 1 4 c. 5 6 - 1 6 1. Rani ate ¼ of an apple. Her brother ate ½ of that apple. What part of the apple is still left? 2. A cake was cut into 12 pieces. 1/3 of it was left out. How many pieces were eaten? 3. What fraction is half of half? 4. How will you add ½ + ¼? (Hint: To add two fractions, denominators should be the same.)

Basic elements of geometry Point : The origin of geometry is from a point. A point has no dimensions. It is represented by a dot (.) Line : A number of points arranged close to each other, one after the other, make a line. In other words, a line is made up of infinite number of points in space. . . . . . . . . . . . . . . . . . . . . . Line Properties of line: A line is made up on infinite number of points A line extends throughout the space. A line has no beginning or end. (It extends to infinity.) It has no end points. A line is represented as Example: Number line. Ray: A ray has a starting point but no end point. It extends to infinity. Example: Sun’s rays; light rays from other sources. A ray is made up of infinite number of points. It has a beginning, but no end. A ray is represented as 0 where 0 is the starting point. 64

Line segment: A line segment is part of a line. It has two end points. Can you find some examples of line segments in nature, in the school, or in the class? It is represented as A ————— B, where A & B are its two end points. Note to remember: In everyday usage, sometimes, we refer to line segments as lines. Example: Draw a line. We cannot draw a line. What we draw is a line segment. Parallel and perpendicular lines/line segments: When two lines maintain the same distance between them throughout, they are said to be parallel. 65 1cm 1cm 1cm Examples of parallel lines are railway lines, electric cables connecting poles, bars of a window etc. Find at least 3 examples of parallel line segments: (a) In your class (b) In your school campus Perpendicular lines: When one line stands vertically over another, they are said to be perpendicular. Some examples of perpendicular line segments are: (a) Corners of a book (b) Corners of a room where the wall meets the floor. Find 5 examples of perpendicular lines (a) In the class (b) In the school

Angles: An angle is formed between two rays starting from the same point. Let us consider a part of the ray OB , and a part another ray OA . The two rays start from the same point . O Thus, an angle is formed between the two rays. This angle can be named as AOB . It is written as AOB . is the sign for an angle . The angle between two perpendicular line segments is 90 degrees . Angles less than 90 degrees are called acute angles , while angles greater than 90 degrees are called obtuse angles . 1. Use your compass or divider to measure these angles. 2. Demonstrate the formation of these angles using your arm. 3. Look for acute angles, obtuse angles, and 90 0 angles in the classroom, at home and in the school. Also observe the objects on your way to school. Look for parallel lines and angles. 66 Acute angle Right angle Obtuse angle 1 centimetre is divided into 10 divisions. Each small mark on a ruler represents 1 millimetre. 10 millimetres = 1 centimetre. Measurement of a line segment Take out your ruler. Observe the markings on the ruler. You can see numbers on the ruler against some markings. Distance between any two long marks on a ruler is 1 centimetre.

How do we use the ruler to measure lengths? Keep the ruler alongside a line segment such that the zero on the ruler falls on one end point of the line segment. See on what mark the other end point of the line segment lies. That mark gives the length of the line segment. 67 In the figure above, B lies on the 5 short mark after 9. So, the length th of AB = 9 cm and 5 mm = 9.5 cm Practice: Find the length of these line segments. Correct upto the millimetre and write below each: (a) A B (b) P Q (c) M N (d) K L Drawing line segments: Draw a line segment 5 cm long. Step 1: Draw a line segment of any length Step 2: Keep the ruler just below the line segment. Step 3: Mark a point on the line segment where the zero of the ruler lies. Step 4: Mark a point on the line segment where the 5 cm mark falls. Name the points as and . A B Step 5: Remove the ruler. AB is the required line segment. Write AB = 5 cm

1. Draw line segments of the following lengths: a. 5.3 cm b. 6 cm c. 4.8 cm d. 3.5 cm 68 1. A line is made up of _____________________ 2. A line has _____________ end points. 3. A ray has ______________ end point. 4. ___________ has 2 end points. 5. Parallel lines have ___________ distance between them everywhere. 6. ____________ lines do not meet. 1. Write down the parallel line segments. 2. Write down the perpendicular line segments. 3. How many angles are there ? 4. Name the acute angles. 5. Measure the sides. Which are equal. 1. Give 2 examples of perpendicular line segments from your surroundings. 2. Give 2 examples of parallel line segments from your surroundings. 3. Give 3 examples each of acute angle, right angle, and obtuse angles from your surroundings. Guided

Plain shapes Problem 1: Look at the figures on the right. Describe the sides and the angles. Name each one. Use a ruler to measure the sides of figs. (1) & (2) Figure 1 Name _______________ Side AB = ________ cm. BC = ________ cm. CD = ________ cm. AD = ________ cm. Are any of the sides parallel? If yes, which sides? _________________________________________________ Figure 2 Name _______________ PQ = ________ cm. QR = ________ cm. RS = ________ cm. SP = ________ cm. Write the parallel sides of the above figure, if any. ___________________________________________________ In fig. (1) & (2), How many angles can you see? What do you know about each angle? Are they acute, obtuse, or right angles? ___________________________________________ ___________________________________________ ___________________________________________ 69 Fig. 1 Fig. 2

Figure 3 What is the figure called? _______________________ How many sides are there in the figure? _____ Name the sides ________________ How many angles does the figure have? ____________ Are there any obtuse/right angles? _________ Figure 4 What do you call this figure? _____________ Are there any sides in the figure? ___________ Are there any angles? ____________ What is the point O called? _____________ Properties of plain figures Rectangle: 1. AB = CD Opposite sides of a rectangle are equal . AD = BC 2. AB || DC Opposite sides are parallel AD || BC A, B, C, and D are called vertices. 3. All the 4 angles of a rectangle are 90 degrees (right angles). 70 Square 1. PQ = QR = RS = SP. All the sides of a square are equal 2. PQ||RS Opposite sides of a square are parallel PS||QR Opposite sides of a square are parallel Square Fig. 3 Fig. 4 Rectangle

3. All the angles of a square are right angles (90 degrees) 4. A,B,C,D are called vertices. 71 A B C A B D C Quadrilateral The figure ABCD is called a quadrilateral It has 4 unequal sides. It has 4 vertices . All the 4 angles of a quadrilateral are different. Circle It has no vertex, and no sides. It has a centre. It has a curved edge. Triangle 1. Sides of a triangle may or may not be equal. 2. There are 3 sides of a triangle. 3. There are 3 angles in a triangle. 4. Two angles of a triangle are always acute. 5. The third angle can be a right angle or an obtuse angle. 6. All the three angles of a triangle can be acute too. The points where the line segments meet in a triangle are called vertices. A, B, C are vertices.

A . 1. A rectangle has _________ sides. 2. Each angle of a rectangle is _____________ . 3. Opposite sides of a rectangle are __________ and __________ 4. A square has __________ equal sides. 5. Each angle of a square is ___________ 6. A rectangle has ____________ sides and _________ angles. 7. A circle has a ___________ edge 8. A quadrilateral has __________ sides which are _________ B. 1. Give 3 examples of rectangular objects. 2. Give 3 examples of square objects. 3. Give 3 examples of triangular objects. 4. Give 3 examples of circular objects. 5. What is common between a square, rectangle and a quadrilateral? 6. What is the difference between a square and rectangle? 7. What is the shape of your maths text book? 8. What is the shape of the blackboard? 9. What is the angle shown by letter 'V' in the english alphabet acute, obtuse or right? 10. What is the angle between the wall and the floor? 72

73 • Take a rectangular sheet of paper. Fold it as shown by the dotted line. • Cut off or tear off the extra part. Open the fold. You will find a square. • On your way to school, look for rectangles, squares, triangles and circles. • Note down the objects and their shapes. • You verified that opposite sides of a rectangle are equal by measuring its sides. You can also verify it by folding a rectangular paper. • Take a rectangular piece of paper. Name its vertices as A, B, C, D. (a) Fold the paper such that DC falls on AB. Thus, you see that DC = AB. (b) Fold the paper again such that BC falls on AD. Thus, you see that AD = BC. • Repeat the same for a square. For a square, you can even fold the paper along the opposite corners. Such a line is called a diagonal. • By folding along the diagonal as in (3), you will see that AB = BC = CD = AD. Square A B D C A B D C A B D C A B D C A B D C 1 2 3

SOLID SHAPES Solid shapes are also called 3D figures. Plane shapes have only two dimensions – vertical and horizontal. Solids have 3 dimensions – vertical, horizontal and angular. We can generate solids from plane shapes. Let’s see what are some common 3D shapes: 1. Cube It is made up of 6 identical squares. Properties: A cube has 6 faces, 8 vertices and 12 edges. All sides of a cube are equal. 2. Cuboid A cuboid is made up of 6 rectangles. 3. Cylinder It has 3 faces, 2 edges and no vertices. 4. Cone It has a curved surface, a circular base and a pointed top. It has 1 vertex, 2 faces and one edge. 5. Pyramid It has a square base, and a pointed top. It has 8 edges, 5 vertices and 5 faces. 6. Sphere: It has a curved surface only. 74 Cube Cuboid Cylinder Cone Pyramid Sphere

Relation between plane shapes and solid shapes: Experiment 1: 75 1. Take a bangle or disc on a circular object. Spin it and see what shape you get. A sphere is generated by a spinning circle. 2. Spin a triangle and see what shape is obtained. 3. Spin a rectangle and see what shape is obtained. (You can cut out a triangle and a rectangle from a cardboard) 4. Draw solids with plain shapes. Experiment 2: Cube Draw a square covering 4 small squares in the grid. Draw another equal square through the middle of the first square. Join the corners of the two squares by slanting lines. You get a cube. Experiment 3: Cubiod Draw 3 plane shapes as shown. Draw the others also and join them. Solids can be drawn on geo dot paper also. The paper can be printed out from the computer. Square Cube Rectangle Cuboid Cone Cylinder Pyramid Rectangle Rectangle

76 1. Name the solid which has 6 identical faces. 2. Name the solid generated by a circle. 3. Name the solid which has one curved surface and 2 plane surfaces. 4. Name the solid which has 5 vertices and 5 faces. 5. Name the solid which has 6 different faces. 1. Name atleast 5 objects having each of the following shapes. You may look for objects in the school or at home. 1. Cube 4. Cone 2. Cuboid 5. Sphere 3. Cylinder 1. How many squares are there in the given picture? 2. How many triangles are there in the given picture? (There are more than what meets the eye) Picture 1 Picture 2

Contents 1. Soil, Rocks and Minerals ........... 78 2. Natural Resources..................... 82 3. Birds .......................................... 88 4. Animal World and Adaptation ................................. 95 Class 3 Term 2

Soil Soil is formed by weathering of rocks. Rocks when exposed to heat and rain for a number of years start crumbling, and in due course of time, become a powdery mass. This process is called weathering. It takes thousands of years for soil formation. Collect samples of soil from different places, for example, garden, playground, roadside, banks of the lakes or ponds etc. Observe them keenly. Are they all the same? Soils in different places vary in texture and colour. 78 Which soil contains less sand? Which soil contains more clay? Which soil contains more sand? Which soil contains more humus? What does soil contain? humus clay sand gravel The above mentioned experiment shows the particles present in soil. However, soil contains something else too. Experiment 1: Take a sample of garden soil. Put a handful of it in a beaker and add water to fill 3/4 of the beaker. Stir well and let it stand. You will see th different layers of sediment in the beaker. Repeat the experiment with other soil samples. Do they all contain the same amount of particles or do they differ? Write down your observations in your note book, along with answers to the following:

Let us see through another experiment. Experiment 2: Take some soil in a boiling tube and heat it from the bottom. You will see that water droplets start forming at the mouth of the boiling tube. What does this experiment show? 79 Experiment 3: Take some soil in a beaker (fill half the beaker). Pour water in the beaker in a very thin stream. You will see bubbles coming out of the soil as water mixes with it. What are those bubbles? What does this experiment show? Soil types Depending on the amount of sand present in the soil, it can be divided into 3 types: 1. Loamy soil: This type of soil is typically found in gardens. It contains sand and clay in the right proportion. It absorbs water and allows water to spread evenly. Loamy soil is suited for growing plants. 2. Clay soil: It contains more clay and less sand. This kind of soil does not allow water to percolate. Instead, it holds all the water that it absorbs. This kind of soil does not allow air circulation too. Thus, it is not suited for growing plants. 3. Sandy soil: It contains more sand, and very little clay. It cannot hold water, and hence it is not suited for growing plants.

Experiment 4: You can verify the above yourself. Take 3 bottles and 3 funnels. Keep the funnels on the bottles. Fill the 3 funnels with garden soil, soil from the playground (sand pit), and soil from a pond (You can ask someone to get it 80 for you). Pour the same quantity of water in all the funnels. After you stop pouring water in the funnels, see which bottle contains more water, and which contains the least amount of water. Enter your observations in your note book. Note: All the funnels must be of the same size. All the bottles should be of the same size too. Sand stone Marble stone Lime stone Quartz stone Granite stone Rocks and Minerals By now, you know that soil is formed from rocks. But what are rocks? Rocks are made up of chemical compounds called minerals. For example, limestone is a rock. It is made up of a compound called calcium carbonate. Marble is also a rock, made up of the same compound. You might have seen glass-like pebbles near lakes and rivers. They are made up of mineral called silica. These rocks are called quartz.

81 Granite is also made of chemical compounds. When rocks crumble to fine particles to form soil, these minerals become part of the soil too. These minerals are essential for plant growth. That is why plants grow in soil. Do you know that precious stones used in jewellery are minerals too? Diamond is the hardest mineral. 1. Texture - Feel of touch 2. Humu s - Decayed plant and animal matter 3. Sand - A chemical compound called silica 4. Gravel - Larger particles of sand, and small pebbles. 5. Weathering - Breaking down of rocks into soil under the influence of sun’s heat, and rain 1. How is soil formed? 2. What does soil contain? 3. What are the different types of soil? How do they differ? 4. What are rocks? 5. Which soil is best for growing crops? • Perform the experiments mentioned in the lesson. • Explain the experiment in your own words, along with your observations. • Collect different varieties of stones and pebbles from your surroundings and display in the class. • Try to get their names.

Natural Resources Nature has provided us with many things, which man can use for a comfortable living. These are called natural resources. They are nature’s gift to man. Air, water, land and minerals are a few among them. Human resources can also be considered as a natural resource. Natural resources can be classified into two types – renewable and non-renewable. Renewable resources: They can be used again and again, and are available forever. Air, water, sun’s energy, and wind are renewable resources. 82

Non-renewable resources: Such resources, once used up, cannot be produced again. Fuels, mineral deposits, coal, and petroleum are non renewable resources. What is human resource? Manpower is the basic requirement for doing any task. Man’s physical strength and intelligence, both come under human resources. In other words, professionally qualified people and daily wage workers together make up human resources. Let us take a look at some natural resources. Land Land is comprised of soil and vegetation. Soil is essential for crop cultivation. A part of the land mass is occupied by forests and grasslands. 83

84 Forests provide us with timber, fruits and other products like honey, lac and gum. Paper production depends on forests too. The grasslands are used as pastures and for agriculture. The main source of our food is agriculture. As population increases, more and more land gets used for agriculture. This leads to grasslands getting all used up, which leads to forests being cleared for agriculture. However, if we keep doing this, we will soon have a situation when we have no more forests. The absence of forests will lead to shortage of many non-renewable sources. For example, forests are the source of fuel. Tribals and villagers depend on dried wood for fuel. With no forests, there will be no fuel available for tribals. Minerals Minerals are present in the Earth in the form of rocks. They are mined and used to extract metals. Coal is a mineral used as fuel. Petroleum is a liquid mineral drilled out from under the Earth. All these minerals are formed millions of years ago. Once they are over, we cannot produce them again. Air Air is a renewable resource. It does not get exhausted. However, pollution makes it unfit for use. Water Water cycle in nature maintains the volume of water on the Earth. The water vapour from oceans form clouds and come back to earth as rain. This rainwater joins the sea again, thus completing a cycle. This is called the water cycle. Water is essential for life. We need water for drinking, bathing, washing clothes etc. Water is essential for agriculture too. Animals also need water to survive.

85 Electricity In the modern day, we depend on electricity for most of our daily tasks. However, the electric energy produced from rivers and coal is not enough to meet the needs of the increasing population. Therefore, alternate sources of energy are being tried out. For example, solar energy is being used for lighting, heating, and for producing electricity. Similarly, force of wind is also being used to produce electricity in some places. “Nature has given enough to satisfy man’s needs, but not his greed.” These words of Mahatma Gandhi are worth recalling now. Man’s greed has disturbed nature’s harmony. Misuse and over-use of natural resources have landed us in great trouble. When all the non-renewable resources are blindly used up, what will man do to meet his needs? Let us not abuse nature and its resources. Distribution of Electricity

86 1. Renewable resources – Resources that can be produced again 2. Non-renewable resources – Resources that once used up can never be produced again 3. Human resource - Skilled and unskilled workers 4. Lac - Secretions of an insect that are used as sealing wax 5. Exhaust - Finish 6. Minerals - Useful compounds that occur naturally. Salt is a mineral. Diamond and coal are minerals too. 7. Harmony - Agreement, or peaceful co-existence. 1. What are natural resources? 2. Differentiate between renewable and non-renewable resources. 3. Explain human resources. 4. How are forests useful to us? 5. Name some minerals used as fuel. 6. What is water cycle? Separate the following into renewable and non renewable sources of energy. Hydroelectricity, coal, wood, charcoal, solar power, wind energy, food crops, cattle, water, air, petroleum, natural gas, minerals Renewable Non - Renewable

87 Why should we not misuse natural resources? Think and write 5-6 lines on the topic. Fill in the bubbles to provide various ways in which manpower is used. human resources agriculture building construction

Birds There are a variety of birds around us. Can you name a few? What are the common features of birds? Of course, the beak, the claws, and the wings are some common features of birds.Like animals, birds differ in their size, colour, length of their beak, shape of their legs/claws and wings. The differences in their body are to suit their feeding habits and movements. 88 Down feathers are found in the body. They are short and fluffy. Penguins are birds that cannot fly. Two other flightless birds are ostrich and kiwi. Body features: Birds can fly in the air. Their body is suited to fly. They have light hollow bones, and wings that help to balance the body in the air. Tail feathers help them to move forward. Feathers: Birds have three types of feathers- body feathers, flight feathers and down feathers. Body feathers are broad and short, while flight feathers are long and flat. Flight feathers are present in the wings.

Beaks Different birds have different beaks. The shape of birds’ beaks depends on the food habit of the birds. Birds that peck on worms, insects, food grains etc. have short, sharp, and pointed beaks. Example: sparrow, pigeon, peacock, hen, crow. Fruit eating birds have curved beaks to scoop out the fleshy fruits and to crack nuts. Example: parrot, macaw etc. The humming bird sucks nectar from flowers. Thus, it has a long, needle-like beak. The woodpecker pecks on the hard trunk of trees to bring out insects and worms. Therefore, its beak is strong, hard, long, and chisel shaped. Have you noticed the beaks of duck, goose, turkey, swan, etc.? They are all swimming birds. They catch fish and other tiny creatures in water. Therefore, their beaks are like ladles or strainers, to help strain the water and retain the animal. Crane stands on its long legs and catches prey with its beak in shallow water. For this purpose, it has a long beak and a long flexible neck. 89 Parrot Sparrow Humming Bird Woodpecker Duck

Eagles, hawks, etc. feed on animals. Their beaks are shaped in such a way as to tear off the flesh of animals. They have a curved, hook like beak. A hawk also eats dead animals. However, the eagle doesn’t. A hawk is also called scavenger of the forest for this reason. 90 Claws of birds: Claws of birds are also suited to their feeding habits and the way they sit while they are not flying. For example, flesh eating birds like eagle, hawk, etc. have strong claws which are spread out. Their claws are called talons. They help them to hold on to their prey. Perching birds like crow, sparrow, pigeon etc. have claws with three toes in front and one at the back. This helps them to hold on to the branches of trees. Hens also have similar claws, but they are flat to enable them to scratch on mud while walking. Birds that keep climbing from branch to branch and from tree to tree in search of fruits and nuts have claws with two toes in front and two at the back. Example: parrot, woodpecker. Claws of Crane Claws of Eagle Claws of Woodpecker Claws of Sparrow Claws of Hen Crane

91 Duck, goose, turkey etc. are swimming birds. They swim in water. Their claws are woven by skin without leaving any gaps in between. This enables them to swim and wade. Their claws are called webbed feet. Flamingo and crane are wading birds. They wade through muddy waters. Their feet are long and stretched out. Nesting habits of birds Most of the birds build nests on trees for laying eggs. Some such birds The Ostrich’s egg is the largest in the world. It is the largest living cell out there. • Mother’s love for the offspring is a common feature among all animals. It is not surprising then that human beings care for their young ones too. • Tiny birds build nests to keep their eggs protected from rain and enemies, and hatch them into young ones. They take pain to fetch food and feed the young ones till they are able to fly. • However, unlike human beings, once birds learn to fly and earn their food, they fly away forever. • Human children prefer to live with their parents forever. are crow, parrot, woodpecker etc. A woodpecker makes holes in tree trunks. Some birds build nests on ceilings of houses, sunshades, hollows in the walls etc. For example: sparrow, pigeon etc. Flamingo Claws of a Duck

92 1. Why do birds have differences in their body features? 2. What are the different kinds of feathers? What are their functions? 3. Name two birds of prey. 4. Why does a woodpecker peck on a tree trunk? 5. Why do ducks have webbed feet? Collect the abandoned nests of weaver bird and tailor bird and display them in the class. The weaver bird builds its nest by weaving fibres. Its nest hangs from the tree. The tailor bird makes its nest by stitching leaves in a conical shape. An eagle makes its nest with twigs on top of a tree. However, a cuckoo never makes a nest. It lays its eggs in a crow’s nest. Penguins build their nest with pebbles on the ground, while a skylark builds its nest in the tall grass in the fields. Pigeon Nest Woodpecker Nest Penguin Nest

93 6. Identify the bird from the beaks: Identify the bird from the clues given: a. Its claws are called Talons _______________ b. This bird has webbed feet _______________ c. It has two toes in front, two at the back _______________ d. It has three toes in front and one at the back _______________ e. It has long and spread out toes _______________ a. ___________ b. ___________ c. ___________ d. ___________ Name one bird that - a. Eats fruits and nuts b. Pecks grains c. Has ladle like beak d. Lays egg in crow’s nest e. Makes nest with pebbles f. Eats other birds and animals g. Cannot fly h. Is called scavenger of the forest.

Which is your favourite bird? Write a short paragraph about the bird. Collect its photograph and paste in the given box. • Make clay models of beaks (including head) of different birds on a wooden board or tile. Do it as group work. Name of the bird About the bird 94

Animal World and Adaptation The earth has a wide variety of animals. Some live with us as pets and domestic animals, while others live in forests. Some animals are plant eating, some of them are meat eating animals, while there are some that eat plants as well as animals too. Animals adapt to their feeding habits and the surroundings that they live in. We have seen how birds have adapted according to their food habits and resting place. The same is applicable to animals too. Let us see how animals adapt to suit their food habits and habitats. Herbivores Animals like cow, goat, horse, donkey, buffalo etc., which are collectively called cattle, eat grass and leaves. They first swallow the food as a whole and store it in their stomach. It is when they are resting at a place that they bring the food back in their mouth and chew it. This is called mastication. Cattle have sharp front teeth and flat back teeth. 95

Carnivores and Omnivores: Animals like lion, tiger etc. eat other animals. They have to tear the flesh of animals and eat them, which requires a lot of force. That’s why such animals have long and curved canine teeth to tear the flesh, and flat hind teeth to chew it. Some animals like rabbit, rat, and squirrels gnaw their food. Generally, they eat grains, vegetables, fruits, cheese, etc. They have sharp front teeth meant for gnawing purposes. Some animals swallow their food whole. For example: snakes, frogs, lizards, crocodiles etc. 96 Zebra Squirrel Lion Rat Rabbits crocodile Insects Cheetah

A snake’s muscles are elastic. A snake can expand its mouth to swallow the prey even if it is bigger than its mouth. However, it cannot lap up liquids, as it has a forked tongue. A frog has a long tongue, which is usually folded in its mouth. At the sight of the prey, it stretches the tongue out, and the prey sticks to the tongue. It is then folded back into its mouth. Some animals can take liquid food. For example: cats and dogs can lap up milk from a plate. On the other hand, a butterfly sucks nectar from flowers. It has a long tube like structure called sucker for this purpose. Mosquitoes suck blood from our body. • In films, they often show snakes lapping up milk. • People in India also offer milk to snakes on Nagapanchami. • However, the fact is that snakes cannot lap up milk. They cannot take liquid food. 97 Snake Frog

98 Adaptations according to habitat Animals have some adaptations to escape from enemies, and also to adjust to climatic changes of their surroundings. The tiger and zebra have black stripes on their body, which help them in camouflage. When they stand in a bush, the stripes can be mistaken for the shadow of grass. In the same way, the spots on leopard or cheetah are also mistaken by enemies. A Cheetah can run very fast to catch its prey. A deer can also run fast. The branched horns of a buck help it to fight the enemy. An elephant has its nose modified into a long flexible trunk. The trunk of an elephant is a multipurpose organ. It can pick up things with the trunk, take food in the trunk and put it in its mouth, and also fight enemies with it. The trunk is used to lift loads too. A cat’s eyes have been adapted such that it can see in the dark. Herbivorous quadrupeds (animals that walk on four legs) have hoofs Elephant Tiger cheetah Zebra

to protect their feet. Carnivores too have clawed hoofs to protect their feet. The clawed feet which help them to tear their prey, are called paws. Camels, which are found in deserts, have wide hoofs. They can live without water for many days. Polar bears found in snow covered lands have a white and thick fur to protect them from cold. They also hibernate during winters. This helps them to conserve their energy. Snakes and frogs too sleep underground during winters. This is called hibernation. Shelter for Animals Domestic animals have shelters made by man, while wild animals live in their natural homes. A lion lives in cave-like gaps in the rocks in a forest. It is called a den. A tiger sleeps inside a thick bush. Monkeys spend most of their time on trees, while snakes live in anthills. Rabbits make burrows and sleep inside them at night. 99 Camel Burrow Bear

Honey bees live in hives made on trees. Shelters of domestic animals Cow - Shed Hen - Coop Horse - Stable Dog - Kennel Bird - Nest Goat, Sheep – Pen 100 Dog - Kennel Cow - Shed Bird - Nest Horse - Stable Goat - Pen