Primary 3 · Statistics
P3 bar graphs
In P3, your child reads bar graphs whose scale counts in 2s, 5s, 10s or more, and uses the numbers to compare, add and find differences. Some questions ask them to draw a missing bar. The first thing to read is always the scale.
- Taught in
- Term 2
- Syllabus
- 2 skills
- Usual slip
- Counting lines as 1s
What your child learns in P3 bar graphs
Two skills, each with what it looks like on a worksheet.
See the syllabus wording
- reading and interpreting data from bar graphs
- using different scales on axis
Read the bars, then use them
Read each bar against the scale, then answer what is asked: which is the most, how many more, or how many altogether. Some questions ask your child to draw a missing bar from a clue.
| Category | Number of pupils |
|---|---|
| Kiwi | 6 |
| Pear | 8 |
| Plum | 4 |
Scales that skip
The scale is often not 1. A line can be worth 2, 5, 10, 50 or more, and the small lines in between split each gap evenly. Check what one line is worth before reading any bar.
| Category | Number of cans |
|---|---|
| 3A | 100 |
| 3B | 200 |
| 3C | 50 |
Key facts and formulas
- Read a bar graphRead where each bar ends on the scale. "How many more" means subtract.how many more on Monday than Tuesday →
Category Number of books Mon 20 Tue 10 Wed 15 - Read the scale firstFind what one step on the scale is worth. Tuesday's bar ends halfway between 20 and 30.half of a step of 10 → Tuesday →
Category Number of cups Mon 30 Tue 25 Wed 40
Words to know
- Scale
- The numbers along the side of the graph, showing what each line is worth.
- Interval
- The gap between two lines on the scale, the same size all the way up.
- Axis
- The line along the side or bottom of a graph. The scale sits on one axis.
The sentence that costs the mark
A bar reaches the 3rd line, and the scale counts in 5s. What is its value?
What the working usually does
3 intervals ×1=3
Counts the 3 lines the bar reaches as if each were worth 1. A careful count, but it skips the scale.
What the question asked
3 intervals ×5=15
Reads the scale first: each interval is 5, so 3 intervals is 15.
Counting to the top of a bar is the right instinct, and 3 is a real number of lines. What changes the answer is what one line is worth. Read the scale before the bar.
The same P3 bar graphs question, worked properly
Lah works through it the way she does every question in StudyLah: one step at a time, marking the picture as she goes.
The bar graph shows the number of books read by four pupils. How many more books did Omar read than Lena?
| Category | Number of books |
|---|---|
| Kai | 35 |
| Lena | 20 |
| Omar | 45 |
| Sara | 30 |
- Before reading the bar graph, check the scale. Each numbered line is 25, and each small line is 5.
- Lena's bar reaches 4 small lines. That is not 4 books. Each small line is 5, so 4 × 5 = 20.
- Omar's bar reaches 45. To find how many more, subtract: 45 − 20 = 25.
- So Omar read 25 more books than Lena.
Every question in StudyLah comes with a walkthrough like this one.
Try it freeThree quick P3 bar graphs questions
Try them together, then tap to check.
Question 1
Four children collected shells. The bar graph below shows how many each found. How many shells were found in total?
| Child | Number of shells |
|---|---|
| Mei | 120 |
| Raju | 150 |
| Sara | 90 |
| Tom | 140 |
Show answer
Answer500. The bars show 120, 150, 90 and 140, and 120 + 150 + 90 + 140 = 500.
Question 2
The bar graph shows the fruits Grocer Pan sold. He sold twice as many watermelons as peaches. How many watermelons did he sell?
| Category | Number of fruits sold |
|---|---|
| Apple | 30 |
| Peach | 8 |
| Durian | 24 |
| Orange | 40 |
| Watermelon | ? |
Show answer
Answer16. Each small line is 2, so the Peach bar shows 8. Twice as many is 2 × 8 = 16.
Question 3
The bar graph below shows how many stickers of each shape a class collected. How many more heart stickers than moon stickers were collected?
| Category | Number of stickers |
|---|---|
| Star | 18 |
| Heart | 13 |
| Moon | 10 |
| Cloud | 6 |
Show answer
Answer3. The Heart bar reaches 13 and the Moon bar reaches 10, so 13 − 10 = 3.
Helping at home
How to tell it has clicked
Show any bar graph and ask what one line up the side is worth, before reading a bar. A child who checks the scale first has it. One who starts counting lines has not.
If a bar three lines up on a 5s scale is read as 3, that is the slip. Point at the numbers on the side, not at the bar.
Try this tonight
Charts are everywhere: a weather app, a step counter, a chart in the newspaper. Cover the bars and ask what each line is worth on this one. The scale changes from chart to chart.
Read one bar together out loud: "three lines, each worth 5, so 15". Saying the scale every time is what makes it stick.
Before and after P3 bar graphs
Builds on
Primary 2 Picture GraphsReads picture graphs with a key
You are here
Primary 3 Bar Graphs
Reads bar graphs with any scale
Head Start
P3 to P4 Maths: what to revise before P4One of three P3 topics to revise before P4 Term 1
Leads to
Primary 4 Pie ChartsReads each sector as a share
Leads to
Primary 4 Tables and Line GraphsReads the right cell and the right point
More in Primary 3
Struggling with the working rather than the topic itself? How to help your child with problem sums
See how your child is doing on this topic
StudyLah marks each step separately, so you can see whether it was the setup or the arithmetic that cost the mark.