Solution: Estimate length Actual length Object a) Maths textbook b) Lunch box c) Water bottle d) Desk e) Duster f) Teacher’s table g) Class cupboard h) H eight of your classroom door 10.2 Comparing Mass and Volume by Estimation I Think Raj knows about heavier and lighter objects. He also knows about the simple balance. His mother told him to find the weight of some fruits using marbles on a simple balance. How can Raj find them? I Recall We have learnt how to tell between the heavy and light objects using a simple balance. Let us answer the following to recall the same. Tick the object that is heavy and cross the object that is light. Measurement 47
Simple balance Objects 48
I Remember and Understand Weight/Mass The pan with the heavier object on the simple balance We can also compare the weights of goes down. The pan with the multiple objects using a simple balance. lighter object goes up. Example 6: Fill in the blanks with the correct numbers. One is done for you. 1 watermelon is heavier than 3 oranges. ____ torches are lighter than ____ laptop. Measurement 49
____ cube is lighter than ____ teddy bears. ____ football is heavier than ____ cricket balls. Example 7: Choose the correct word from the brackets. One is done for you. 1 cricket bat is heavier (heavier/ lighter) than 5 bananas. 50
2 hens are ______________ (heavier/lighter) than 1 dog. 1 crab is ______________ (heavier/ lighter) than 2 fish. 3 bricks are ______________ (heavier/lighter) than 3 books. Volume/Capacity Different containers can hold different quantities of water or milk or oil. Let us see an example. Example 8: Tick the vessel/container that can hold more water. One is done for you. Measurement 51
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? Train My Brain Compare the weights of these objects and fill in the blanks. a) b) ______ apples are heavier ______ carrots are lighter than ______ tomatoes. than ______ teapot. I Apply When the objects on both the pans of a simple balance weigh the same, both the pans are at the same level. Example 9: Fill in the blanks with the correct number. One is done for you. 2 cabbages weigh as much as 1 pumpkin. Measurement 53
____ apples weigh as much as ____ mango. ____ oranges weigh as much as ____ capsicums. ____ apples weigh as much as ____ basketball. Example 10: Compare and write 1, 2, 3 and 4 below the following vessels. Write 1 for the vessel that holds the least quantity of water. Write 4 for the vessel that holds the most quantity of water. One is done for you. 54
4 31 2 Measurement 55
I Explore (H.O.T.S.) We can guess some objects to be heavier than or lighter than the given objects. Let us see an example. Example 11: Fill in the blanks with the name of an object that is heavier or lighter than the given object. One is done for you. a) A spoon is lighter than a cricket bat. b) A pineapple is heavier than a __________. c) A feather is lighter than a __________. 56
d) A helmet is heavier than a ______________. Maths Munchies A Lick was used by the Greeks to measure the distance from the tip of the thumb to the tip of the index finger. Hand span, cubit, pace and lick are non-standard units of measurements of length or distance as they differ from person to person. Connect the Dots English Fun Let us read the poem aloud: We don’t have a ruler, but it’s okay, We can measure things another way. What do you see around the room, to help us measure this really long broom. I see pencil, I see cubes, I see many things that we can use. The broom is 15 pencils and 50 cubes tall. This is non-standard measurement for you all. Measurement 57
EVS Fun A blue whale can weigh as much as 30 elephants and be as long as 3 large buses. Drill Time 10.1 Measure Lengths Using Non-standard Units 1) Find the lengths of the objects with the help of the given smaller objects. a) b) c) d) 58
10.2 Comparing Mass and Volume by Estimation 2) Choose the correct word from the brackets. 4 books are 3 potatoes are 1 toy car is ___________ ____________ ____________ (heavier/lighter) (heavier/lighter) (heavier/lighter) than 2 soda cans. than 1 helmet. than 3 bulbs. 3) Fill in the blanks with the correct numbers. ____ apples weigh ____ potatoes weigh ____ cricket balls as much as ____ as much as ____ weigh as much as oranges. tomatoes. ____ football. Measurement 59
4) Write 1 for the object that holds the least quantity of water. Write 4 for the object that holds the most quantity of water. 60
A Note to Parent Help your child to make a simple balance using a stick, thread and paper plates. He or she can use it to compare the weights of their play things. This will enhance their understanding of weights and the use of a simple balance. Measurement 61
11Chapter DHaatnadling I Will Learn About • reading a pictograph. • presenting information through a pictograph. 11.1 Pictographs I Think Raj saw fruits of different colours in a basket. He wanted to count the number of fruits of each colour. How should Raj note them down? I Recall Let us recall the concepts that we have already learnt. Data: A series of facts collected for some particular use is called data. Collection: A group of objects or items taken together is called a collection. 62
Arun has some toys with him as shown in this picture. Observe his collection and answer the questions. Cars Cars Bus Truck Cycle Bus Bike a) How many toys does Arun have? [ ] b) Which toy is maximum in number? [ ] c) Which toys are minimum in number? [ ] d) How many toy cars does Arun have? [ ] e) How many toy buses does Arun have? [ ] I Remember and Understand In class 1, we have learnt to make collections. We showed a collection by drawing pictures of the given things. Data Handling 63
Consider the following examples of collections: 1) List of students in a class whose names begin with the letter ‘S’. List of students in a class whose names begin with the letter ‘S’. S. No. Name of the Student 1) Sampath Kumar 2) Sai Nikilesh 3) Srikanth 4) Sharath Chandra 5) Suraj 6) Saritha 7) Sowjanya 8) Sukanya 2) List of people with their phone numbers. List of people with their phone numbers S. No. Name of the person Phone number 1) Sharath Chandra 9246070416 2) Saritha 9413820164 3) Sukanya 9964712741 4) Suraj 9347938472 5) Sowjanya 9834562366 3) List of different types of dresses. List of different dresses S. No. Dress Number of dresses 1) 2) Frocks 5 3) Jeans 9 T-shirts 4 64
In the same way, a) m ake a list of the objects in your school bag. b) make a list of things you take on a picnic. Making a list of items may take a lot of time if there are many items. Hence, it is necessary to use a pictograph. A key on a pictograph tells us how many objects Pictograph: Listing the different data items each picture stands for. using picture symbols is called a Pictograph. To read a pictograph, we: a) look at the given key. b) multiply the given number of pictures with the value of the key. Consider these examples. Example 1: If = 10 strawberries, then means how many strawberries? Solution: = 10 strawberries (Given). So, = 3 × 10 strawberries = 30 strawberries Example 2: If = 4 cupcakes, then means how many cupcakes? Solution: = 4 cupcakes (Given) So, = 2 × 4 cupcakes = 8 cupcakes Example 3: The number of cakes baked in a week is given in a pictograph. Observe the given pictograph and answer the questions. Data Handling 65
Key: = 5 cakes Day of the week Number of cakes baked in the week Sunday Monday Tuesday Wednesday Thursday Friday Saturday a) How many cakes were baked on Thursday? b) On which day were the highest number of cakes baked? c) On which day were the least number of cakes baked? d) How many cakes were baked on Wednesday? Solution: a) N umber of cakes baked on Thursday = 1 =1 × 5 cakes = 5 cakes 66
b) The highest number of symbols given is for Sunday. So, the highest number of cakes were baked on Sunday. c) The least number of symbols given is for Thursday. So, the least number of cakes were baked on Thursday. d) T he number of symbols given for Wednesday is 3. So, the number of cakes baked on Wednesday is 3 × 5 cakes = 15 cakes. ? Train My Brain Your class plans to watch a movie. The teacher asks you to pick a symbol and a key. The number of students who want to watch each movie is given. Make a pictograph based on the data given. 14 children voted for The Little Mermaid. 10 children voted for The Toy Story. 12 children voted for Inside Out. 8 children voted for Bolt. I Apply Let us learn more about pictographs through these examples. Example 4: The number of students in a class having pets is given in the pictograph. Understand it and answer the questions. Key: 1 = 4 students, 1 = 2 students Data Handling 67
Pet Number of students a) How many students are present in the class? b) How many students have a pet dog? c) How many students have a pet cat? d) Which pet does the maximum number of students have? e) Which pet does the minimum number of students have? Solution: a) 1 = 4 students So, 10 = 4 × 10 students = 40 students = 2 students 68
So, 3 = 6 students S o, the total number of students present in the class = 40 + 6 = 46 students. b) 1 = 4 students So, 3 = 3 × 4 students = 12 students 1 = 2 students So, number of students who have a pet dog = 12 + 2 = 14. c) 1 = 4 students So, 2 = 2 × 4 students = 8 students 1 = 2 students So, the number of students who have a pet cat = 8 + 2 = 10. d) T he maximum number of symbols is given for the dog. So, most of the students have dogs as pets. e) T he minimum number of symbols is given for the fish. So,the least number of students have fish as pets. Example 5: The given pictograph shows the grades that students of Class 2 got in an exam. Read the pictograph and complete the table. One is done for you. Key: = 2 students; = 1 student A+: Excellent, A: Very Good, B+: Good B: Fair, C: Better, D: Satisfactory, F: Fail Data Handling 69
Exam results of the students of Class 2 Grade Students Number of students A+ 3×2=6 A B+ B C D F Total a) How many students are there in the class? b) How many grades are there? c) How many students failed in the exam? d) How many students got A+ grade? e) Which grade is obtained by the most number of the students? 70
Solution: a) Grade Number of students A+ 6 A 9 B+ 13 B 8 C 7 D 4 F 1 48 Total There are 48 students in the class. b) There are 7 grades. c) 1 student failed in the exam. d) 6 students got A+ grade. e) Maximum number of students got the B+ grade. I Explore (H.O.T.S.) We have learnt how to read a pictograph. Now, let us learn how to draw a pictograph when data is given. Example 6: The number of flower pots sold by a nursery in one day are: 12 Marigolds 21 Jasmines 9 Tulips 6 Daisies 6 Lilies Data Handling 71
Represent the data in the form of a pictograph. Key: = 3 flower pots Solution: = 3 flower pots 12 ÷ 3 = 4; 21 ÷ 3 = 7; 9 ÷ 3 = 3; 6 ÷ 3 = 2; 6 ÷ 3 = 2 Flower pots sold on a day Marigold Jasmine n Tulip Daisy Lily Maths Munchies Pictographs are also known as pictograms. They are not only used in Maths but also in other subjects. Their use started many years ago when pictures were the main form of writing. 72
Connect the Dots English Fun Did you know that the word ‘pictograph’ comes from the Latin language? ‘Picto’ means picture and ‘graph’ means writing. EVS Fun Make a list of the students in your class who come to school by bus, bicycle and auto rickshaw. Do you think we can use a pictograph to decide the mode of transportation used the most? Drill Time 11.1 Pictographs Solve the following: 1) The pictograph shows the number of students in each group. Use the pictograph to answer the questions. Key: 1 = 5 students Data Handling 73
Group Number of students Group 1 Group 2 Group 3 Group 4 Group 5 a) Which group has the maximum number of students? b) How many students are there in Group 4? c) Which group has 20 students? 2) The pictograph shows the number of sharpeners with each student of Grade 2. Use the pictograph to answer the questions. Key: 1 = 2 sharpeners and = 1 sharpener 74
Name of the Number of sharpeners student Rita Sunita Rakesh a) W ho has the minimum number of sharpeners? b) How many sharpeners are there in all? c) Who has eight sharpeners? 3) The pictograph shows the number of toffees each child ate. Use the pictograph to answer the questions. Name of the child Number of toffees Vinay Suresh Mahesh Reena = 3 toffees Key: 1 Data Handling 75
a) Who ate the minimum number of toffees? b) W hich child ate three toffees? c) W ho ate the maximum number of toffees? A Note to Parent Let your child help you in planning his or her coming birthday celebration. To decide the menu, help your child make a list of the dish each guest likes. Let him or her then record the results and draw a pictograph. 76
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