Year 3 maths: Counting and number patterns-Number lines

Number lines are a great way to compare numbers. They also help you to order numbers, understand place value and estimate where a number is.

This number line shows you numbers increasing in hundreds to 1000.

 

By looking at the number line, you can see how far 100 and 1000 are away from each other.

Example 1:

What number is being shown on the number line to 100?

 
 

Step 1 – Work out what each interval represents

The difference between 50 and 100 is 50. You can check this:

100 – 50 = 50

Next, count the number of intervals. There are 10 in total.

How many 10s go into 50? 5.

So each interval increases by 5 each time.

 
 

Step 2 – Count the number of intervals

Count the number of intervals, starting at 50. There are 7 intervals.

As each interval represents 5, the calculation we need is:

7 x 5 = 35

Now we can work out the answer. The number line starts at 50:

50 + 35 = 85

We can double check by counting 7 intervals from 50 on the number line. The arrow reaches the number 85.

Example 2:

Estimate the value of the arrow.

 

Step 1 – Figure out where the halfway point is

The number line goes from 0 to 1000.

The easiest thing to do first is to figure out where the halfway point, 500, is. This will help estimating the value of the arrow easier!

Now you can see that the arrow is closer to 500, so the number must be between 0 and 500.

 

Step 2 – Split the section into equal intervals

You can use the arrow to help you. If you split it into 5, the intervals will represent 100.

The arrow is pointing to the 4th interval.

As each interval is 100, you can estimate that the arrow is pointing to 400.

Example 3:

Where would you estimate 690 to be on this number line?

The intervals on the number line are going up in hundreds.

690 will sit between 600 and 700.

690 is closer to 700 than 600. It is also past the halfway point between the numbers.

The arrow would be very close to 700 like this:

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