When you work out a sum with more than one operation, eg 8 + 2 × 3, follow the BIDMAS rule. Without this rule you could get different answers - so getting the order of operation correct is important.

There is an agreed order of operations in Maths called BIDMAS.

BIDMAS stands for **B**rackets, **I**ndices, **D**ivision and **M**ultiplication, **A**ddition and **S**ubtraction.

All of these terms are fairly obvious except for 'Indices' - which are just powers, eg or .

'Indices' are also known as 'orders', which gives us the term BODMAS (**B**rackets, **O**rders, **D**ivision and **M**ultiplication, **A**ddition and **S**ubtraction).

So the order you should do your calculations in is:

- Brackets
- Indices
- Division and Multiplication (start on the left and work them out in the order that you find them)
- Addition and Subtraction (when only addition and subtraction are left in the sum, work them out in the order you find them - starting from the left of the sum and working towards the right)

What is ?

If you calculate the part first you get:

If you calculate the part first you get:

These are two very different answers, but only one is correct.

In BIDMAS, multiplication comes before addition, so multiply by first:

, so this is the right answer.

What is ?

This sum has only addition and subtraction. So work them out from left to right:

Notice that if you didn't go from left to right you would get a different answer:

That would be incorrect, which is why we work them out from left to right.