Finding the Range Revision | KS3 Maths Resources

## What you need to know

Things to remember:

• To find the range of a set of data, we subtract the biggest from the smallest.
• Be careful with negative numbers, your range should always be positive.

In statistics, “the range” gives us an idea of how spread out all of the data is.

Find the range of the following numbers:

2 4 8 1 5 6

Putting the numbers in order from biggest to smallest will help us see how spread out the numbers are.

1 2 4 5 6 8

Ordering the numbers like this lets us see that the data is between 1 and 8. To find the range, we just need to find the difference between these numbers.

$$8-1=7$$

Range = 7

So really, all we need to know are the biggest and smallest numbers to find the range.

We find the range using 3 steps.

Find the range of the following numbers:

0.4 0.7 1.2 3.5 2.5 3.1

Step 1: Find the biggest number

3.1

Step 2: Find the smallest number

0.4

Step 3: Subtract the smallest from the biggest

$$3.1-0.4$$

Range = 0.7

Find the range of the following numbers:

-5 -2 1 -6 3

Step 1: Find the biggest number

3

Step 2: Find the smallest number

-6

Step 3: Subtract the smallest from the biggest

$$3 - - 6=3+6=9$$

## KS3 Maths Revision Cards

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## Example Questions

Step 1: Find the biggest number

8.4

Step 2: Find the smallest number

2.3

Step 3: Subtract the smallest from the biggest

$$8.4-2.3=6.1$$

Step 1: Find the biggest number

5

Step 2: Find the smallest number

-6.3

Step 3: Subtract the smallest from the biggest

$$5 - -6.3=11.3$$

## KS3 Maths Revision Cards

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