Bigger bar charts and rounding · Usually met around P4
Reading bar charts with big numbers
Find what a square stands for, then read the bar.
How to do it
Method
Find what a square stands for, then read the bar
4 × 50 = 200
Another way
Read across to the scale
The bar's top lines up with 200
In full
With big data, each square of a bar chart stands for 10, 50, 100 or so. First read the numbers up the side: the gap between neighbouring lines is what one square stands for. To read a bar, see which number its top lines up with: 4 squares high at 50 a square is 4 × 50 = 200; a top half-way between lines adds half a square, half of 50. To compare two things, subtract their values; don't just count squares. Or check by following the bar's top across to the scale and reading it off.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
What does each square up the side of this bar chart stand for?
- A. 50
- B. 100
- C. 500
- D. 1
Choose the right answer
Show the answer and working
Answer: A. 50
Neighbouring lines up the side are 50 apart, so each square stands for 50.
Example 2
The bar chart shows how many of four foods there are. How many more 🍪 than 🍌 are there?
Show the answer and working
Answer: 450
🍪: 500; 🍌: 50. 500 − 50 = 450.
Example 3
The bar chart shows how many of four foods there are. How many 🍌 are there?
Show the answer and working
Answer: 50
The 🍌 bar stops half-way between two lines, so add half a square (50): 50.
Practise it in the game →Bigger bar charts and rounding · Free to start, unlimited questions, no download