7. To draw a bar graph we have to first chose a convenient scale.

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1 BOOK 6 ( CBSE ) / Chap 9 / Data Handling Chapter Facts : 1. Facts or figures ( numeric or alpha-numeric) collected with a definite purpose are called data. 2. Information collected by the investigator herself or himself with a definite is called primary data or raw data. 3. After collection data is condensed by organizing it in a tabular form using tally marks. [ means 1, means 2, means 3, means 4, means 5, means 6 and so on. ] 4. Data can also be represented pictorially. This can be done using a pictograph or a bar chart. 5. A pictograph represents data through pictures of objects. A picture may be used to represent one or many units. 6. Data can expressed pictorially by using bar graphs also. In a bar graph, bars of uniform width are drawn horizontally or vertically with equal spacing between them. The length of each bar represents the given number. 7. To draw a bar graph we have to first chose a convenient scale. Most convenient scales. 1cm = 1 unit ; 1cm = 2 units ; 1cm = 5 units ; 1cm = 10 units ; 1cm = 20 units ; 1cm = 50 units ; 1cm = 100 units ; 1cm = 200 units ; 1cm = 500 units ; 1cm = 1000 units ; 1cm = 2000 units ; 1cm = 5000 units. etc. 8. Interpreting a given bar graph means drawing conclusions from the information given by it. 9. When the information was gathered from a source which already had the information stored, the data obtained is called secondary data. Such a source may newspapers, journals, magazines, internet etc. Formative Assessment A ) Multiple Choice Questions. In each of the following tick the correct option. 1. Using tally marks, which one of the following represents the number seven: (a) (b) (c) (d). 2. A number was represented using tally bars as follows :. The number is Copyright with the author. 1

2 (a) 18 (b) 33 (c) 19 (d) The marks (out of 20) obtained by 10 students in test are listed as below: 17, 18, 15, 18, 13, 18, 10, 10, 13, 11. The number of students who obtained marks less than or equal to 13 is (a) 4 (b) 3 (c) 5 (d) 2 4. The marks (out of 10) obtained by 25 students in a test are listed as below: 7, 8, 5, 8, 3, 8, 10, 10, 3, 4, 8, 7, 8, 9, 2, 8, 1, 2, 6, 5, 5, 5, 0, 1, 9. The number of students who obtained marks more than 7 is (a) 10 (b) 11 (c) 9 (d) The ages of 10 students in bus are listed as below: 11, 12, 10, 13, 13, 14, 10, 10, 13, 11. The number of students who are less than 12 years of age is (a) 4 (b) 5 (c) 3 (d) 2 6. The choices of the fruits of 20 students in a class are as follows: B, M, A, G, M, A, B, G, M, B, A, O, B, G, A, G, B, G, A, G, [A, B, G, M and O stand for the fruits Apple, Banana, Grapes, Mango and Orange respectively] Which two fruits are liked by an equal number of students? (a) A and M (b) A and B (c) B and O (d) B and G 7. According to data of the above question, which fruit is liked by most of the students? (a) O (b) G (c) M (d) A 8. In a frequency table maximum frequency was observed to be 105. A bar graph is to be drawn to represent the data. The most convenient scale to chose is (a) 1 cm = 10 unit (b) 1 cm = 1 units (c) 1 cm = 100 units (d) 1 cm = 50 units 9. A bar in a bar chart is 2.5 cm tall. If scale is 1 cm = 20 units then this bar represents (a) 25 units (b) 100 units (c) 200 units (d) 50 units 10. In a pictograph represents 8 boxes. How many such symbols are needed to represent 20 boxes? (a) 2 (b) 3 (c) 2.5 (d) not possible to represent. B ) Fill in the blanks 3. A table showing how many times has each value occurred is called a. 4. A represents data through pictures of objects. Copyright with the author. 2

3 6. Data gathered from a source which already had the information stored is called data. 8. In a pictograph, if a symbol represents 20 flowers in a basket then stands for flowers. 9. While drawing a bar graph to represent the ages of different persons in a group, scale was taken as 1 cm = 5 years. The age of a person for whom the bar has been drawn 7 cm long is. C ) True / False State whether the given statements are true (T) or false (F). 3. In a bar graph the width of the bars may be different. T/ F 4. In a bar graph there may or may not be gap between the bars. T/ F 5. bars of a bar graphs cannot be represented horizontally. T/ F 7. To represent the ages of children in a family using a bar graph, it is convenient to take one unit length to represent one year. T/ F 8. Data which can be represented as a bar graph cannot be represented as a pictograph. T/ F D ) True false with Justification Say true or false for each of the following. Justify your answer 2. Number of children in a class was represented by in a pictograph, where stands for 10 students. Now the same data has to be represented by a bar graph using scale 1 cm = 2 students. The length of the bar for the same class is 15 cm. T/ F 5. To represent the population of different cities using a bar graph, it is convenient to take one unit length to represent one person. T/ F E ) Matching Match the following : 1. Column I shows the maximum frequency in a data and column II shows the scale. Match each item of Column I with the corresponding item of Column II to have most appropriate scale. Column I Column II (i) 52 A. 1 cm = 1 units (ii) 196 B. 1 cm = 2 units Copyright with the author. 3

4 (iii)515 C. 1 cm = 5 units (iv) 1120 D. 1 cm = 10 units (v) 12 E. 1 cm = 20 units (vi) 110 F. 1 cm = 50 units G. 1 cm = 100 units Formative Assessment 1 mark Q s 1. In a data the observation 7 has appeared 12 times. How will this be represented using tally marks? 2. What is the frequency corresponding to? 3. In a pictograph represents 8 persons. How many persons are represented by? 4. In a pictograph represents 2 items. How will 10 items be represented? 5. Maximum frequency of a data is A bar graph is to be drawn for this data. What would be the appropriate scale if it is desired that the longest bar is around 10 cm tall? 6. To draw a bar graph scale was taken as 1 cm = 500 units. What frequency is represented by a bar which is 3.6 cm tall? 7. Bar in a bar graph is 7.8 cm tall. The scale used is 1 cm = 1000 units. What frequency is represented by this bar? 8. A bar 6 cm tall represents the frequency What is the scale used? 2 mark Q s 1 The blood groups of 25 students are recorded as under: A, B, O, A, AB, O, A, O, B, A, O, B, A, AB, AB, A, A, B, B, O, B, AB, O, A, B. Arrange the information in a table using tally marks. 2. Sale of electric bulbs on different days of the week (Sunday closed ) is shown in the pictograph below. [ = 5 bulbs ] Mon Thu Tue Fri Wed Sat a) How many bulbs were sold on Wednesday? b) On which day were the maximum number of bulbs sold? Copyright with the author. 4

5 c) On which day were minimum number of bulbs sold? d) If each bulb is sold for Rs 18, then what is the sale on Friday? Rs 3. Circulation of daily newspapers in different languages in a small town is shown in the bar chart below. a) How many newspapers are daily circulated in Hindi and Urdu taken together? b) Newspapers in which language(s) have a daily circulation of above 5000? c) Circulation of which newspaper is more than that of Urdu but less than that of Hindi? d) What is the daily circulation of newspapers in the town? questions: 4. The bar graph given below represents approximate length (in km) of some National Highways in India. Study the bar graph and answer the following questions: (a) Which national highway among the above is the longest? (b) Which national highway among the above is the shortest? (c) What is the length of National Highway 9? (d) Length of which national highway is about three times the national highway10? 3 mark Q s Copyright with the author. 5

6 1. Ram tossed a dice 20 times and obtained the following results : 5, 2, 3, 5, 4, 6, 6, 5, 4, 2, 1, 3, 2, 2, 3, 5, 2, 4, 6 and 2. Make a table for this data using tally bars. a) How many times did he get 6? b) Which number did he get most number of times? c) Which number did he get least number of times? d) How many times did he get a number less than 3? 2. The number of students in a middle school in different years is shown in the table given below. Prepare a pictograph using a to represent 100 students. Year Number of students The number of items sold by a shopkeeper on six consecutive days of a week is as follows. Day Sun Mon Tue Wed Thu Fri Sat Number of items sold Draw a bar chart to represent the above information.( draw vertical bars ) 4. Number of mobile phone users in various age groups in a city is listed below: Age group(in years) Number of mobile users Draw a bar chart to represent the above information.( draw horizontal bars ) 5. Read the following bar graph and answer the questions that follow. Copyright with the author. 6

7 a) What information is provided by the given bar graph? b) Which two states had same production in ? c) Which state has same production in both years? d) Which state has maximum production in ? e) Which state has a production of 60 million tones in ? f) What is production of West Bengal in ? 4 mark Q s 1. The number of ATMs of different banks in a city is shown below: Bank Number of ATMs Syndicate Bank 5 Dena Bank 15 Indian Bank 20 State Bank of India 25 Vijaya Bank 10. Draw a pictograph to represent the above data and answer the following questions. a) Which bank has maximum number of ATMs in the city? b) What is the total number of ATMs in the city? 2. Home appliances sold by a shop in one month are given as below: Home appliance Number of home appliances Refrigerator 65 Television 35 Washing Machine 20 Copyright with the author. 7

8 Cooler 50 DVD Player 30 Draw a bar graph ( draw vertical bars ) to represent the above information and answer the following questions. a) Which appliance has the minimum monthly sale? b) In all how many refrigerators and televisions were sold in the month? 3. In a botanical garden, the number of different types of plants are found as follows: Type of the plant Number of plants Herb 50 Shrub 60 Creeper 20 Climber 45 Tree 95 Draw a bar graph ( draw horizontal bars ) to represent the above information and answer the following questions: (a) Which type of plant is maximum in number in the garden? (b) Which type of plants are less than 50 in number? 4. The following bar - graph gives the information about the number of railway tickets sold for different cities on a railway ticket counter between 5.00 am to am. Draw a pictograph to represent the data represented in the bar graph above. 5. Students of a class were given a task to count the number of articles made of different materials in a room. The information collected by them is represented as follows: Copyright with the author. 8

9 Material Used Article [ = 20 items ] Wood Glass Metal Rubber Plastic Draw a bar ( draw vertical bars ) graph to represent the data represented in the pictograph above. End.. ANSWERS Formative MCQ s 1 d 2 a 3 c 4 c 5 b 6 b 7 b 8 a 9 d 10 c Fill in the blanks 1 frequency table 2 pictograph 3 secondary True False 1 F 2 T 3 F 4 T 5 F True False with Justification. 1 T ; Number of students = 10 x 3 = 30 Length of bar = 30 / 2 = 15 cm 2 F ; This will make bars very long. It will not be convenient to represent them on paper etc. Matching (i) - C, (ii) - E, ( iii) - F, (iv) - G, (v) - A, (vi) D Copyright with the author. 9

10 Summative One mark questions 1 //// //// / cm = 200 units cm = 400 units Two marks questions 1 Blood group Tally marks Number of students. 2 a) 25 b) Wed O //// / 6 c) Thu A //// /// 8 d) Rs 270 B //// // 7 AB //// 4 3 a) Rs 12,000 b) English and Hindi c) English d) 21,000 4 a) NH 2 b) NH 10 c) 900 km d) NH 3 Three marks questions 1 a) 6 b) 2 c) 1 d) 7 2 Pictograph Copyright with the author. 10

11 5 a) Coal production in million tones in some Indian states. b) UP and AP c) UP d) MP e) MP f) 30 million tons Four marks questions 1 Key : = 5 ATM s 2 Bank Number of ATMs Syndicate Bank Dena Bank Indian Bank State Bank of India Vijaya Bank 3 5 a) State Bank of India b) 75 a) tree b) creeper and climber a) Washing Machine b) Key : * = 10 tickets City Number of tickets Patna ******** Jaipur ***** Delhi ********** Chennai **** Gauhati *** End. Copyright with the author. 11