Reading a pictograph and its key
A class makes a chart where one small picture of a book means 20 books borrowed from the library. A long row of book pictures instantly tells which day was busiest. That chart is a pictograph.
A pictograph (चित्रालेख) shows data with pictures or symbols. The key (scale, सूची) tells how many items one symbol stands for. Number of items = number of symbols × value of one symbol.
In the figure : Fruit sold: each symbol is 10 kg, so apple 5 symbols = 50 kg.
Rule 1: Read the key first — Count the symbols and multiply by the key.
- Easy : Key: 1 symbol = 20 books. 6 symbols = 6 × 20 = 120 books.
- Medium : Key: 1 symbol = 50 students. 4 symbols = 200 students.
- Exam-type : Key: 1 symbol = 8 pencils. 7 symbols = 56 pencils.
In the figure : 3 full symbols and a half symbol show 35 when 1 symbol = 10.
Rule 2: Half symbol — A half symbol means half the value of the key.
- Easy : Key 1 symbol = 10. 2 full symbols and a half = 20 + 5 = 25.
- Medium : Key 1 symbol = 4. A half symbol = 2.
- Exam-type : Key 1 symbol = 50. 3 symbols and a half = 150 + 25 = 175.
Reading a pictograph and its key
In the app you can move this figure with your finger.
Open in the appAlways find the key first. Without it the symbols mean nothing.
Counting symbols as the answer, forgetting to multiply by the key.
Memory clue: Key first, count next, multiply last.
Spot the difference
| Part | What it tells |
|---|---|
| Symbol | one unit of data |
| Key | value of 1 symbol |
| Half symbol | half of the key |
Practice questions
- 1Key: 1 symbol = 20 books. How many books are shown by 6 symbols?
- 2Key: 1 symbol = 50 students. What do 4 symbols show?
- 3Key: 1 symbol = 8 pencils. What do 7 symbols show?
- 4Key: 1 symbol = 10. What do 2 full symbols and a half show?
- 5Key: 1 symbol = 4. What does a half symbol show?
- 6Key: 1 symbol = 50. What do 3 and a half symbols show?
- 7A row has 8 symbols and the key is 1 symbol = 25 kg. How many kg?
- 8Ravi sees 5 symbols and says 5 books. The key is 1 symbol = 20 books. Correct him.
Show answers (try them yourself first)
- 1120
- 2200 students
- 356 pencils
- 425
- 52
- 6175
- 7200 kg
- 85 × 20 = 100 books.
Answering questions from a pictograph
The chart says: rice 6 symbols, wheat 4 symbols and dal 3 symbols, where 1 symbol = 5 kg of grain sold. Which sold most? How much more than dal? We answer from the key and the symbols.
To answer questions: (1) read the key, (2) count symbols in each row and multiply, (3) compare rows or add them. Most symbols = biggest. Fewest symbols = smallest.
Rule 1: One row — Value of a row = symbols × key.
- Easy : Rice: 6 × 5 = 30 kg.
- Medium : Wheat: 4 × 5 = 20 kg. Dal: 3 × 5 = 15 kg.
- Exam-type : Rice sold 3 symbols more than dal: 3 × 5 = 15 kg more.
Rule 2: Difference and total — Difference = difference in symbols × key. Total = total symbols × key.
- Easy : Rice − dal = (6 − 3) × 5 = 15 kg.
- Medium : Total symbols = 6 + 4 + 3 = 13. Total = 13 × 5 = 65 kg.
- Exam-type : Cars sold, key 1 symbol = 20: Mon 3, Tue 5, Wed 2 and a half → 60, 100, 50. Total = 210 cars.
Add the symbols first and multiply once; it is quicker.
Subtracting the symbols and forgetting the key. 3 symbols less is 15 kg, not 3.
Memory clue: Rows tell the story: biggest row, smallest row, then do the sums.
Spot the difference
| Question | How to find |
|---|---|
| Most | row with most symbols |
| Difference | (symbols difference) × key |
| Total | (all symbols) × key |
Practice questions
- 1Key 1 symbol = 5 kg. Rice has 6 symbols. How many kg?
- 2Which grain sold the most: rice (6), wheat (4) or dal (3)?
- 3Which sold the least?
- 4How many kg of wheat were sold?
- 5How much more rice than dal was sold?
- 6Find the total grain sold.
- 7Key 1 symbol = 20 cars. Mon 3, Tue 5, Wed 2 and a half. Find the total cars.
- 8Sita says rice is 3 kg more than dal because the difference is 3 symbols. Correct her.
Show answers (try them yourself first)
- 130 kg
- 2Rice
- 3Dal
- 44 × 5 = 20 kg
- 515 kg
- 613 × 5 = 65 kg
- 710.5 symbols × 20 = 210 cars
- 83 symbols × 5 = 15 kg more.
Choosing a scale and drawing a pictograph
A shopkeeper wants to show sales of 15, 30, 45 and 60 mangoes. Drawing one picture for each mango would be too long. He chooses 1 picture = 15 mangoes, which gives 1, 2, 3 and 4 pictures.
To draw a pictograph: choose a scale that divides all the numbers neatly, then divide each number by the scale to get the symbols. A bigger scale gives fewer symbols; a smaller scale gives more.
In the figure : The same number 20 with scales 1, 4 and 10: bigger scale, fewer symbols.
Rule 1: Choose the scale — The scale should divide every number, or leave only halves.
- Easy : For 15, 30, 45, 60 use scale 15: 1, 2, 3, 4 symbols.
- Medium : For 12, 24, 36 use scale 12: 1, 2, 3 symbols.
- Exam-type : 42 cannot be shown exactly with scale 10 (4.2 symbols). Use scale 6: 42 ÷ 6 = 7 symbols.
Rule 2: Symbols from numbers — Symbols = number ÷ scale.
- Easy : 30 ÷ 5 = 6 symbols.
- Medium : 75 ÷ 25 = 3 symbols.
- Exam-type : 90 ÷ 20 = 4 and a half symbols (90 = 4 × 20 + 10).
Choosing a scale and drawing a pictograph
In the app you can move this figure with your finger.
Open in the appA half symbol shows only half the scale, so 42 with scale 10 is not possible.
Using a scale that gives too many symbols, like 1 symbol = 1 for 500. Choose 1 symbol = 100.
Memory clue: Big scale – few pictures; small scale – many pictures.
Spot the difference
| Scale | Symbols for 60 |
|---|---|
| 1 symbol = 5 | 12 |
| 1 symbol = 10 | 6 |
| 1 symbol = 20 | 3 |
Practice questions
- 1Draw how many symbols for 30 with scale 5?
- 2How many symbols for 75 with scale 25?
- 3How many symbols for 60 with scale 10?
- 4Choose a good scale for 15, 30, 45 and 60.
- 5How many symbols for 90 with scale 20?
- 6Why is scale 10 not good for 42? Suggest a better scale.
- 7A shop sold 500 pens. Which is better: 1 symbol = 1 pen or 1 symbol = 100 pens? Why?
- 8Data: 25, 50, 75. Give a scale and the symbols for each.
Show answers (try them yourself first)
- 130 ÷ 5 = 6
- 23
- 36
- 415 (or 5). Symbols: 1, 2, 3, 4.
- 54 and a half
- 642 ÷ 10 = 4.2, not a whole or half symbol. Use scale 6 or 7: 42 ÷ 6 = 7.
- 71 symbol = 100 pens: only 5 symbols instead of 500.
- 8Scale 25: 1, 2, 3 symbols.
Tally marks and tables
You ask your friends their favourite fruit and make a mark for each answer – a vertical line for every vote. After four lines you cross them with a fifth. You are using tally marks.
Tally marks (ताळचिन्हे) count as we survey. Four lines and a fifth across them make a group of 5. Then make a table, add to find the total and draw the pictograph.
In the figure : Tally marks in groups of five show red 8, blue 12 and green 5.
Rule 1: Reading tally marks — Count the groups of 5, then add the single lines.
- Easy : 2 groups and 3 lines = 10 + 3 = 13.
- Medium : 1 group and 2 lines = 7; 4 groups = 20.
- Exam-type : 9 votes are drawn as 1 group and 4 lines.
Rule 2: From tally to table and pictograph — Count each tally, write the number, add for the total, then choose a scale.
- Easy : Mango 9, banana 6, orange 5 → total 9 + 6 + 5 = 20 children.
- Medium : Most liked: mango (9). Least liked: orange (5). Difference = 4.
- Exam-type : Scale 1 symbol = 2 children: mango 4 and a half, banana 3, orange 2 and a half symbols.
Tally marks and tables
In the app you can move this figure with your finger.
Open in the appA table with the total is a good check: the numbers should add up to the number of people surveyed.
Drawing the fifth line beside the group instead of across it.
Memory clue: Four lines up, fifth line across = 5.
Spot the difference
| Fruit | Votes |
|---|---|
| Mango | 9 |
| Banana | 6 |
| Orange | 5 |
Practice questions
- 1How many is 2 groups and 3 lines?
- 2How many is 1 group and 2 lines?
- 3How many is 4 groups?
- 4Show 9 votes in tally marks.
- 5Mango 9, banana 6, orange 5: find the total.
- 6In the same data, which fruit is most liked and which is least liked?
- 7Use scale 1 symbol = 2 children. How many symbols for mango, banana and orange?
- 8Rita says 4 lines and a line beside them is 5. What should she do?
Show answers (try them yourself first)
- 113
- 27
- 320
- 41 group of 5 and 4 lines
- 520
- 6Mango (9) most, orange (5) least.
- 74 and a half, 3, 2 and a half
- 8Draw the fifth line across the four to make a group.
Comparing and interpreting data
A shopkeeper compares notebooks sold in four days. Looking at the pictograph, he sees at a glance which day was best and how much sales went up or down.
A pictograph helps us compare, find totals, averages and changes. Average = total ÷ number of items. Change = (symbols difference) × key.
In the figure : Ice-creams sold on four days: 18, 30, 24 and 36, total 108.
Rule 1: Compare and total — Find each value, compare, then add.
- Easy : Notebooks: Mon 40, Tue 60, Wed 30, Thu 50. Best day: Tuesday (60).
- Medium : Total = 40 + 60 + 30 + 50 = 180.
- Exam-type : Tue − Wed = 60 − 30 = 30 more notebooks.
Rule 2: Average and change — Average = total ÷ number of days. Change = later − earlier.
- Easy : Average = 180 ÷ 4 = 45 notebooks a day.
- Medium : Cycles in 4 months: 20, 40, 30, 30 → total 120, average 30.
- Exam-type : Wheat: 5 symbols in 2018, 8 symbols in 2022, 1 symbol = 30 tonnes. Increase = 3 × 30 = 90 tonnes.
Always write the unit with the answer: books, kg, tonnes.
Dividing by the number of symbols instead of the number of days for the average.
Memory clue: Compare – add – share (average).
Spot the difference
| Question | Method |
|---|---|
| Which is more? | compare symbols |
| Total | add all |
| Average | total ÷ number of days |
Practice questions
- 1Notebooks: Mon 40, Tue 60, Wed 30, Thu 50. Which day is best?
- 2Find the total notebooks sold.
- 3How many more notebooks on Tuesday than Wednesday?
- 4Find the average notebooks sold per day.
- 5Cycles in 4 months: 20, 40, 30, 30. Find the total and the average.
- 6Wheat was 5 symbols in 2018 and 8 symbols in 2022. Key: 1 symbol = 30 tonnes. Find the increase.
- 7Mon 40 and Thu 50: how many more on Thursday and in symbols with key 1 symbol = 10?
- 8Anil finds the average of 40, 60, 30, 50 by dividing 180 by 18 symbols. What is the right method?
Show answers (try them yourself first)
- 1Tuesday
- 2180
- 330
- 4180 ÷ 4 = 45
- 5Total 120, average 30.
- 63 × 30 = 90 tonnes
- 710 more = 1 symbol.
- 8Divide the total by the number of days: 180 ÷ 4 = 45.