Passport-G4-Textbook-Maths-FY

Drill Time Concept 12.1: Multiply and Divide Lengths, Weights and Capacities 1) Convert: a) 2000 cm to m b) 5000 g to kg c) 5000 m to km d) 8000 mℓ to ℓ 2) Multiply: a) 85 kg 145 g ×10 b) 5 ℓ 225 mℓ × 65 c) 7 m 450 cm × 25 d) 5 km 150 cm × 12 3) Divide: a) 34 kg 450 g by 6 b) 50 ℓ 225 mℓ by 5 c) 17 m 85 cm by 9 d) 42 kg 420 g by 7 A Note to Parent Show your child various measurements written on various packaged goods. For example, milk packet, ice-cream packet, wheat flour packet, and so on for them to be able to visualise different measurements used in the household. Measurements 147 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 151 28-12-2017 15:11:24

Chapter Data Handling 13 I Will Learn About • reading and interpreting bar graphs. • drawing bar graphs based on the given data. Concept 13.1: Bar Graphs I Think Jasleen attended a fruit festival conducted for a week in her school. She was asked to give a report on the sale of different fruits per day in the form of a graph. Till then Jasleen only knew how to represent the data as a pictograph. She wanted to find an easier and simpler way of representation. How do you think Jasleen would have given the report? 13.1 28-12-2017 15:11:24 I Recall Recall these points: • The information collected for a specific purpose is called data. • The information given as numbers is called numerical data. • The information shown in the form of pictures is called a pictograph. We have already learnt about pictographs. Let us recall them through the following. 148 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 152

Let us recall the pictographs through the following example. The favourite sports of Class 4 students are given. Read the pictograph and answer the questions. Key: 1 = 6 students Favourite Sports of Class 4 Students Volleyball Cricket Basketball Kabaddi Football a) The most favourite sports of Class 4 students is _____________ . b) The least favourite sports of Class 4 students is _____________ . c) The number of students who like to play basketball is___________ . d) The number of students who like to play football is _____________ . e) The number of students who like to play kabaddi is _____________ . 13.1 I Remember and Understand While drawing pictographs, we choose a relevant picture to represent the given data. If the data is large, it is tedious and time consuming to draw a pictograph. Data Handling 149 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 153 28-12-2017 15:11:24

An easier way of representing data is the bar graph. It uses The bars in a Bar Graph rectangular bars of the same width. can be a drawn either horizontally or vertically. Bar graphs are drawn on a graph paper. A suitable title is given for the bar graph. Let us understand how to read and interpret bar graphs. Example 1: The marks scored by Kamala in a monthly test are represented using a bar graph as given. Understand the graph and answer the questions that follow. Scale: X-axis: 1 cm = 1 subject; Y-axis: 1 cm = 5 marks Kamala’s Performance in a Monthly Test English Maths Science Social Music Hindi Studies Subjects a) What is the title of the graph? b) In which subject did Kamala perform the best? c) In which subject does Kamala need to improve? 150 28-12-2017 15:11:24 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 154

d) What are Kamala’s total marks? Solution: a) The title of the graph is “Kamala’s Performance in a Monthly Test”. b) T he height of the bar representing Maths is maximum. It means that, Kamala performed the best in Maths. c) The height of the bar representing Social Studies is the minimum. So, Kamala needs to improve in Social Studies. d) Kamala’s total marks are 35 + 47 + 42 + 28 + 32 + 40 = 224 Example 2: Information about a primary school is represented in the form of a bar graph as shown. Observe the graph carefully and answer the questions that follow. Scale: X-axis: 1 cm = 1 class; Y-axis: 1 cm = 5 students Strength of Primary School l oohcS Class strength Class a) What is the total strength of all the 5 classes? Data Handling 151 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 155 28-12-2017 15:11:24

b) Which class has the least strength? c) Which class has the greatest strength? d) What is the title of the graph? Solution: a) Total strength is 42 + 36 + 38 + 43 + 45 = 204 b) Class 2 c) Class 5 d) Strength of a Primary School Train My Brain Fill in the blanks. a) A bar graph is used to represent ___________________. b) _________________ bars are used in a bar graph. c) Bar graphs are drawn on __________. 13.1 I Apply We have learnt how to read and interpret bar graphs. Now, let us learn to draw a bar graph. Steps to draw a bar graph: Step 1: Draw one horizontal line and another vertical line, called the axes. They meet at a point called the origin. Step 2: Take a suitable scale such as 1 cm = 5 units. Step 3: On the X-axis, show the items of the data and on the Y-axis show their values. Step 4: Draw bars of equal width on the X-axis. The heights of the rectangles represent the values of the data which are given on the Y- axis. Step 5: Give a relevant title to the bar graph. Let us understand this through an example. Example 3: The following pictograph shows the number of scooters manufactured by a factory in a week. 152 28-12-2017 15:11:25 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 156

Complete the pictograph. Then draw a bar graph for the same data. Key: 1 = 5 scooters Weekday Scooters manufactured in a week Number of scooters Monday Tuesday Wednesday Thursday Friday Saturday Solution: Total Step 1: Let us follow these steps to draw a bar graph. Step 2: Count the number of pictures in the pictograph. Complete the table by writing the product of the number of pictures and the number of scooters per key. Take a graph paper and draw the X and Y axes meeting each other at one corner as shown. Data Handling 153 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 157 28-12-2017 15:11:25

Step 3: Choose a suitable scale. Since the maximum number of scooters is 30 and the minimum is 10, we can take the scale as 1 cm = 5 scooters. Mark weekdays on the X-axis as 1 cm = 1 weekday. Mark the number of scooters manufactured on the Y-axis from 0 to 35. Number of scooters manufactured Mon Tues Wed Thurs Fri Sat X - axis Weekdays 154 28-12-2017 15:11:25 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 158

Step 4: On the X-axis, mark 30, 15, 20, 25, 20 and 10 against the Y-axis as shown. We can plot these points two points apart. Number of scooters manufactured Step 5: Monday Tuesday Wednesday Thusday Friday Saturday Weekdays Draw vertical rectangular bars from these points for each weekday on the X-axis. Give a suitable title to the graph. Weekly Manufacturing of Scooters Number of scooters manufactured Monday Tuesday Wednesday Thusday Friday Saturday Weekdays Data Handling 155 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 159 28-12-2017 15:11:25

We can draw the same graph using horizontal bars by interchanging the values on X and Y axes. Weekly Manufacturing of Scooters Weekdays Number of scooters manufactured Example 4: The number of roses sold during a month in Roopa’s shop is given in the table Week Number of roses sold 1st week 148 2nd week 165 3rd week 130 4th week 172 Represent the data in a bar graph. 156 28-12-2017 15:11:25 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 160

Solution: Scale: X-axis: 1 cm = 1 week;Y-axis: 1 cm = 20 roses Roses sold Weeks 13.1 Train My Brain I Explore (H.O.T.S.) Consider a few real-life examples where we represent data using a bar graph. Example 5: In 2010, the heights of Ramu, Somu, Radha and Swetha were noted as 130 cm, 125 cm, 115 cm and 120 cm respectively. After two years, their heights were again noted as 140 cm, 132 cm, 124 cm and 128 cm respectively. Draw a bar graph to represent the data and answer the questions that follow. a) Who was the tallest among the friends in 2010? b) Who was the shortest among them during 2012? c) How much taller was Ramu than Somu in 2010? d) Whose height has increased the maximum in 2 years? Data Handling 157 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 161 28-12-2017 15:11:25

e) Arrange the children’s heights in 2010 in ascending order and their heights in Solution: 2012 in descending order. Name Height in 2010 Height in 2012 Ramu 130 cm 140 cm Somu 125 cm 132 cm Radha 115 cm 124 cm Swetha 120 cm 128 cm Scale: On X-axis: 2 cm = 1 student On Y-axis: 1 cm = 20 cm Comparison of Heights Height (in cm) Names of children 28-12-2017 15:11:25 158 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 162

a) As the bar for Ramu’s height in 2010 is the highest, Ramu is the tallest among the children. b) R adha is the shortest among them in 2012. (Shortest bar in 2012). c) Ramu is 5 cm (130 – 125) taller than Somu. d) Increase in the heights of the children in the two years: Ramu: (140 – 130) cm = 10 cm S omu: (132 – 125) cm = 7 cm Radha: (124 – 115) cm = 9 cm Swetha: (128 – 120) cm = 8 cm 7 cm < 8 cm < 9 cm < 10 cm Therefore, Ramu’s height increased the maximum in 2 years. e) Heights of the children in 2010: 130 cm, 125 cm, 115 cm, 120 cm Ascending order: 115 cm, 120 cm, 125 cm, 130 cm Heights of the children in 2012: 140 cm, 132 cm, 124 cm, 128 cm Descending order: 140 cm, 132 cm, 128 cm, 124 cm Example 6: The weights of four children are noted in 2014 and 2016 as given. Draw a bar graph and answer the questions that follow. Name Weight in 2014 Weight in 2016 Ram 30 kg 34 kg Shyam 34 kg 32 kg Reema 28 kg 31 kg Seema 29 kg 31 kg a) Who weighed the most in 2014 and 2016? b) Whose weight has decreased in 2016 from 2014? c) Name the two children who were of the same weight in 2016. d) Whose weight in 2014 is the same as that of another child in 2016? Data Handling 159 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 163 28-12-2017 15:11:25

e) W rite the weights of the children in 2014 in descending order and their Solution: weights in 2016 in ascending order. Scale: O n X-axis: 2 cm = 1 student; Y-axis: 1 cm = 5 kg Comparison of Weights Comparison of Weights Weights (in kg) Ram Shyam Reema Seema Names of children a) Shyam was the heaviest in 2014 and Ram was the heaviest in 2016. b) Shyam’s weight decreased in 2016 from 2014. c) Reema and Seema are of the same weight in 2016. d) Shyam’s weight in 2014 is equal to Ram’s weight in 2016. e) Weights in 2014: 30 kg, 34 kg, 28 kg, 29 kg Descending order: 34 kg, 30 kg, 29 kg, 28 kg Weights in 2016: 34 kg, 32 kg, 31 kg and 31 kg Ascending order: 31 kg, 31 kg, 32 kg, 34 kg 160 28-12-2017 15:11:25 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 164

Maths Munchies 213 Data handling is used to organise data properly. Here is the simplest use of data handling. Make a list of your marks in each subject, in each test on a sheet of paper. Add them for each test and know your report card even before your teacher gives you one. Compare the marks with those obtained in the previous test. This helps you to identify the areas you need to concentrate more and prepare well for the forthcoming exams. Connect the Dots Social Studies Fun The population of different states can be compared using a bar graph. English Fun Make a list of your favourite authors. Count the number of books that you know of each author. Using this data, draw a bar graph. (Some names of authors for reference: J K Rowling, Ruskin Bond, C S Lewis, Charles Dickens, R K Narayan and so on.) Data Handling 161 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 165 28-12-2017 15:11:25

Drill Time Concept 13.1: Bar Graphs 1) The score of students in an essay writing competition are given in the table. Draw a bar graph. Subject Marks scored Piyush 65 Suman 72 Vaishnavi 82 Pooja 93 2) The table shows the marks secured by Rajeev in Test 1 and Test 2. Subject Marks in Test 1 Marks in Test 2 Hindi 65 68 English 78 80 60 85 Mathematics 88 80 Science 54 65 Social Studies Compare his performance in the two tests by drawing a bar graph and answer the questions that follow. a) Find Rajeev’s total marks in Test 1 and Test 2 separately. b) In which of the two tests did he perform well with respect to Mathematics? c) In which subject(s) has he improved from Test 1 to Test 2? d) In which of the two tests has Rajeev got less marks? 3) The approximate monthly attendance of Grade 4 is shown in the pictograph given. Draw a bar graph and answer the questions that follow. 162 28-12-2017 15:11:25 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 166

Drill Time Attendance Month June July August September October November Key: 1 = 10 students Data Handling 163 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 167 28-12-2017 15:11:26

Drill Time a) In which month is the attendance maximum? b) In which month is the attendance minimum? c) In which months is the attendance less than 45? A Note to Parent From newspapers or magazines, find out the bar graphs and explain what they are about. Explain the terms mentioned in the bar graph first to give the background and then form basic questions from the same. You may choose articles of common interest like cars, bikes, movies, travel, hobbies and so on. 164 28-12-2017 15:11:26 JSNR_BGM_9789387552753-Passport-G4-Textbook-Maths-FY_Text.pdf 168