Marking on the number line
You learn to put a number in the right place on a number line.
How to work it out
- Find the big mark just before your number.
- Look how much one small mark is.
- Count the small marks forward until you get to your number.
A worked example
Place 38 on the line
- Find the big mark before 38: that is 30.
- One small mark is worth 1.
- Count on 8 marks: 30 + 8 = 38.
More examples
Place 45 on the line
- Find the big mark before 45: that is 40.
- One small mark is worth 5.
- Count on 1 mark: 40 + 5 = 45.
Place 370 on the line
- Find the big mark before 370: that is 300.
- One small mark is worth 10.
- Count on 7 marks: 300 + 70 = 370.
Watch out
You put 38 on the eighth mark from the start, instead of after the 30.
Start at the big number just before it. That is where you start counting the small marks.
Tips
- Say out loud what one small mark is worth before you start counting.
- If the number is close to the next big mark, count back from that mark instead.
Why it works
A number like 38 lies between 30 and 40, and those are big marks. From 30 you count on along the small marks. That way you never have to count from 0, and you put every number in exactly the right place.