Order of operations: BIDMAS

​​In a nutshell

The order of operations is a rule for which operation must be performed first. It is very helpful when having to solve questions involving multiple steps such as multiplication and subtraction.

BIDMAS

BIDMAS is an acronym which identifies the order of operations. 

Note: If there is multiplication and division together in a question, the operation which comes first when  reading from left to right is completed first. The same applies to addition and subtraction. 

Example 1

Calculate: $$30-3\times(8 -1).$$

Use BIDMAS to follow the order of operations and calculate the answer.

 Brackets must be completed first:

​$$8-1=7$$

The expression is now:

​$$30-3\times7$$

​

​There are no Indices, or Division so move onto Multiplication:

$$3\times7=21$$

The expression is now:

​$$30-21$$

​

​​Finally, there is no Addition so move onto Subtraction:

​$$30-21=9$$​

Therefore,

$$\underline{30-3\times(8-1)=9}$$

​