Watch: Counting up and down on a numberline
Number lines are a great way to see where a number is compared to another number.
They also help you to order numbers, understand place value and estimate where a number is.
This video explains how to count up and down from 10,000 using a number line.
This number line shows numbers increasing in thousands up to 10,000.
Charlie is completing a 10,000 m run for charity. He has run 4000 m so far.
By looking at the number line, you can see that Charlie has to run 6,000 m more in order to complete the 10,000 m run.
Here are some more examples to practise how to estimate, draw and label numbers on a number line.
Example 1
Can you estimate what number is shown on the number line?
The arrow seems to be exactly half way between 5,000 and 10,000.
To find out what number that is, first you have to find the difference between 10,000 and 5,000.
10,000 鈥 5,000 = 5,000
Then halve it.
5,000 梅 2 = 2,500
Now you can add 2,500 to 5,000 to work out what the number in the middle is.
5,000 + 2,500 = 7,500
As an estimate, the number must be around 7,500.
Example 2
What number is being shown on this number line?
First, work out what the intervals represent.
There are 10 intervals between 7,500 and 10,000. The difference between these two numbers is 2,500.
To find out what each interval is worth, work out how many tens are in 2,500.
2,500 梅 10 = 250
This means that each interval is worth 250.
You can count up in 250s to get to the arrow or work out 4 lots of 250 and add it on to 7,500. This is because the arrow is 4 intervals from the 7,500 mark.
4 x 250 = 1,000
7,500 + 1,000 = 8,500
So the number shown on the line is 8,500.
Example 3
Could you mark 4,100 on a number line?
4,100 is much closer to 4,000 than 5,000. You would have to draw the arrow just after 4,000!
Activity
Quiz
NEW! Play Guardians: Defenders of Mathematica - the Halloween update. gameNEW! Play Guardians: Defenders of Mathematica - the Halloween update
Experience Mathematica as you鈥檝e never seen it before, with all-new backgrounds and costumes for Halloween. Available for a limited time only. Use your maths skills to save the day before it's too late!
More on Rounding and estimating
Find out more by working through a topic
- count5 of 6
- count6 of 6
- count1 of 6
- count2 of 6