Chapter 4 — Data Handling and Presentation
Complete, step-by-step solutions to every question with figures, charts & clear explanations.
Collecting Data · Tally Marks & Frequency · Pictographs · Bar Graphs · Infographics
💡 In-text Questions
Answers to the in-text prompts, “Math Talk” boxes and worked examples within the chapter.
(4.1 Collecting & Organising Data) To figure out the most popular game in their class, what should Navya and Naresh do?
A single opinion is not enough — they need to look at the whole class. So they should collect data from everyone and then organise it.
(4.2 Pictographs) In the travel pictograph (☺ = 1 student), which mode of travel is used by the most students, and which by the least?
Count the symbols in each row — each ☺ stands for one student.
(4.2 Worked Example) Nand Kishor’s pictograph (▲ = 10 children) shows how often children slept at least 9 hours. Find how many Always, Sometimes, and Never.
Always: 5 full symbols → \(5\times10=50\).
Sometimes: 2 full symbols and 1 half → \(2\times10 + \tfrac12\times10 = 20+5 = 25\).
Never: 4 full symbols → \(4\times10 = 40\). These 40 children never sleep 9 hours, i.e. they always sleep less than 9 hours.
(4.2 Drawing a Pictograph) Lakhanpal showed 1 student as one ☺. His friends had large numbers (present students), so Jarina used ☺ = 5 and Sangita used ☺ = 10 (with a half symbol for 5). What is the advantage of a larger key?
When numbers are large, one-symbol-per-item needs too many symbols and too much space. Choosing a bigger scale/key (one symbol = 5 or 10) makes the pictograph compact, and a half symbol handles the leftover 5.
(4.2 Math Talk) What problems arise in preparing such a pictograph if the total number of students present in a class is 33 or 27?
With a key of ☺ = 10 and a half symbol = 5, we can only show multiples of 5 neatly.
(4.3 Bar Graphs, Example) The bar graph shows India’s population (in crores) each decade. How much did the population increase over the 50 years, and in each decade?
Read the bar tops: 36, 44, 54, 68, 84, 102 (crores).
Over 50 years: \(102-36 = 66\) crores.
Each decade: \(44-36=8\), \(54-44=10\), \(68-54=14\), \(84-68=16\), \(102-84=18\) crores.
(4.3 Bar Graphs in real life) Newspapers and TV often show bar graphs. What does this one tell us at a glance?
The bars grow taller from left to right, so the total keeps rising each year.
📝 Exercise Questions
Detailed solutions to all the “Figure it Out” exercises, section by section.
Section 4.1 — Collecting & Organising Data
What would you do to find the most popular game among Naresh’s and Navya’s classmates?
The raw name-and-game list is hard to read. Organising it groups equal answers together.
What is the most popular game in their class?
Counting each game from the list: Hockey 8, Kabaddi 6, Cricket 6, Satoliya 5, Football 4, Badminton 2.
Try to find out the most popular game among your classmates.
This is an activity to do in your own class.
Pari wants to answer the questions below. Tick (✓) those needing data collection and cross (✗) those that don’t:
a. Most popular TV show among her classmates? b. When did India get independence? c. How much water is wasted in her locality? d. What is the capital of India?
A question needs data collection when the answer is not already known and varies from place to place; general facts do not.
Complete the sweets table (using the tally marks) to help Shri Nilesh: a. jalebi? b. barfi? c. gujiya? d. rasgulla? e. gulab jamun?
| Sweet | Tally | No. of Students |
|---|---|---|
| Jalebi | ||||̅ | | 6 |
| Gulab jamun | ||||̅ |||| | 9 |
| Gujiya | ||||̅ ||||̅ ||| | 13 |
| Barfi | ||| | 3 |
| Rasgulla | ||||̅ || | 7 |
Each completed group of five (̶||||) is 5; count the leftover single marks.
Is the above table sufficient to distribute each type of sweet to the correct student? Explain. If not, what is the alternative?
The table gives only how many chose each sweet, not who chose what.
Sushri Sandhya’s shoe-size data, arranged in ascending order:
3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 7
Find: a. largest size b. smallest size c. students with size 5 d. students with size > 4.
Read directly from the ordered list and count.
How did arranging the data in ascending order help to answer these questions?
Are there other ways to arrange the data?
Record the trees you see on the way to school and fill a table (Peepal, Neem, …). a. Which tree was most? b. Which least? c. Any two equal?
This is a data-collection activity.
Count the letters c, e, i, r, x in a news clipping. a. most frequent letter? b. least frequent? c. list c, e, i, r, x in ascending order of frequency (most people get x, c, r, i, e). Why?
This is an activity, but the order is predictable.
Section 4.2 — Pictographs
The pictograph shows books borrowed in a week from Middle School, Ginnori. a. On which day were the minimum books borrowed? b. Total books during the week? c. On which day were the maximum borrowed, and a possible reason?
Each book symbol = 1 book. Count each row; the empty row is the minimum, the longest row the maximum, and the sum of all rows is the weekly total.
Magan Bhai sold kites to six shopkeepers: Chaman 250, Rani 300, Rukhsana 100, Jasmeet 450, Jetha Lal 250, Poonam Ben 700. Draw a pictograph (🪁 = 100 kites) and answer: a. symbols for Rani? b. who bought the most? c. Jasmeet or Chaman? d. Is Poonam Ben’s more than double Rani’s?
With 🪁 = 100 kites, each 100 is one symbol and 50 is a half symbol:
d. Double of Rani \(= 2\times300 = 600\); Poonam Ben \(=700 = 600+100\), which is more than 600.
Section 4.3 — Bar Graphs
Using the bar graph of students absent in each class: 1. In Class 2, ___ students were absent. 2. Which class had the maximum absent? 3. Which class had full attendance?
Read each bar’s height (1 unit = 1 student). The tallest bar is the maximum; the zero-height bar means nobody was absent (full attendance).
The bar graph shows vehicles at a Delhi crossing each hour, 6 a.m.–noon (1 unit = 100 vehicles). 1. Total cars 6 a.m.–noon? 2. Why so little traffic 6–7 a.m.? 3. Why heaviest 7–8 a.m.? 4. Why less each hour after 8 a.m.?
Add the bar values: \(150+1200+1000+800+700+600\).
\[150+1200+1000+800+700+600 = 4450\]
Section 4.4 — Drawing a Bar Graph
Using the bar graph of Imran’s family monthly expenditure: 1. Most and second-most spending? 2. Is electricity about half of education? 3. Is education less than one-fourth of food?
Values: House rent ₹3000, Food ₹3400, Education ₹800, Electricity ₹400, Transport ₹600, Miscellaneous ₹1200.
2. \(400 = \tfrac12\times 800\). 3. One-fourth of food \(= \tfrac{3400}{4} = 850\), and \(800 < 850\).
Samantha’s tea-garden data — Mites 6, Caterpillars 10, Beetles 5, Butterflies 3, Grasshoppers 2. Help her draw a bar graph.
Take 1 unit length = 1 insect and draw a bar for each, as high as its count:
Pooja’s bar graph of tickets sold was partly erased. a. Tickets for Vidisha? b. for Jabalpur? c. the scale? d. draw Sagar’s bar. e. add the vertical scale. f. are Seoni and Indore correct?
Vidisha’s bar is 6 units and equals 24 tickets, so \(\text{scale}= \dfrac{24}{6}=4\) tickets per unit. Using this scale on the true data (Vidisha 24, Jabalpur 20, Seoni 16, Indore 28, Sagar 16):
Chinu listed transport passing his house (9–10 a.m.). a. Make a frequency table. b. Which was used most? c. How would you collect this data?
Tallying Chinu’s list gives:
| Means of Transport | Number |
|---|---|
| Bike | 13 |
| Car | 6 |
| Bicycle | 8 |
| Auto rickshaw | 8 |
| Scooter | 9 |
| Bus | 4 |
| Bullock cart | 2 |
Roll a die 30 times, record each result, and make a tally frequency table. Find the number appearing: a. minimum times, b. maximum times, c. equal number of times.
This is a hands-on activity (results differ each time).
Faiz’s table of wickets Bumrah took in his last 30 matches. a. What information does it give? b. A suitable title? c. What caught your attention? d. In how many matches did he take 4 wickets? e. Can Mayank total the wickets by adding 0+1+…+7? f. How to correctly find the total?
| Wickets Taken | No. of Matches |
|---|---|
| 0 | 2 |
| 1 | 4 |
| 2 | 6 |
| 3 | 8 |
| 4 | 3 |
| 5 | 5 |
| 6 | 1 |
| 7 | 1 |
To get the total wickets, multiply each wicket value by its number of matches, then add:
\[0(2)+1(4)+2(6)+3(8)+4(3)+5(5)+6(1)+7(1)\]\[=0+4+12+24+12+25+6+7 = 90\]
The pictograph shows tractors in five villages (🚜 = 1 tractor). a. Smallest number? b. Most tractors? c. How many more does C have than B? d. Komal says “D has half of E” — is she right?
Count the tractor symbols in each row (Village A 6, B 5, C 8, D 3, E 6).
The pictograph shows girl students per class (👧 = 4 girls). a. Class with the least girls? b. Difference between Classes 5 and 6? c. If 2 more girls join Class 2, how does the graph change? d. Girls in Class 7?
Each full symbol = 4 girls and a half symbol = 2 girls; read each row accordingly.
Mudhol dogs — A 18, B 36, C 12, D 48, E 18, F 24. Prepare a pictograph and answer: a. a useful scale? b. symbols for Village B? c. Kamini says B + D together exceed the other four villages — right?
All the numbers are multiples of 6, so a key of 🐕 = 6 dogs works neatly:
c. \(B+D = 36+48 = 84\); other four \(= 18+12+18+24 = 72\); and \(84 > 72\).
Survey of 120 students’ free-time activity: Playing 45, Reading story books 30, Watching TV 20, Listening to music 10, Painting 15. Draw a bar graph (1 unit = 5 students). Which is most preferred other than playing?
With 1 unit = 5 students, bar heights are \(45/5=9,\ 30/5=6,\ 20/5=4,\ 10/5=2,\ 15/5=3\) units:
Bar graph of saplings planted in one week. a. Total on Wednesday and Thursday? b. Total for the whole week? c. Greatest and least days, and possible reasons?
Read the bars: Mon 50, Tue 40, Wed 30, Thu 40, Fri 50, Sat 60, Sun 40.
a. \(30+40 = 70\). b. \(50+40+30+40+50+60+40 = 310\).
Shagufta and Divya’s bar graph of tigers in India (2006–2022) has mistakes compared with their table. Find and fix them.
The table says: 2006 → 1400, 2010 → 1700, 2014 → 2200, 2018 → 3000, 2022 → 3700. Comparing each bar with the table, only 2022 matches. The correct graph is:
Section 4.5 — Artistic & Aesthetic Considerations
(Artistic & Aesthetic Considerations) The table lists the tallest mountain on each continent. How much taller is Everest than Koscuiszko? Why is a bar graph clearer than the table?
| Continent | Tallest Mountain | Height |
|---|---|---|
| Asia | Everest | 8848 m |
| S. America | Aconcagua | 6962 m |
| N. America | Denali | 6194 m |
| Africa | Kilimanjaro | 5895 m |
| Europe | Elbrus | 5642 m |
| Antarctica | Vinson Massif | 4892 m |
| Australia | Koscuiszko | 2228 m |
\(8848 – 2228 = 6620\) m. A bar (or column) graph turns these numbers into lengths, so heights can be compared at a glance instead of reading many figures.
In the mountain infographic, taller triangles were also drawn wider, and Everest looks about twice as tall as Elbrus. Is that accurate? What is \(5642\times 2\)?
\(5642\times 2 = 11284\) m, but Everest is only \(8848\) m — not double Elbrus. Also, making taller mountains wider adds information (width) that isn’t real.
To show the heights of the tallest persons in each class, would you use vertical or horizontal bars? Why?
For a table of the longest rivers on each continent, would you use vertical or horizontal bars? Why?
Educational solutions compiled from NCERT Ganita Prakash, Grade 6 · for practice & revision · @edugrown
