The acronym BODMAS
Brackets
Of
Division
Multiplication
Addition
Subtraction.
It is a convention to ensure everyone carries out a question such as that below in the same order. Numbers in brackets are worked out first, followed by multiplication and division with addition and subtraction last.
3 + 5 x 2 =
One way to do the question is: 3 + 5 = 8. 8 x 2 = 16.
It can also be done like this: 5 x 2 = 10. 10 + 3 = 13.
If you use a calculator and key in 3 + 5 x 2 you might get 16 or 13, it depends on the type of calculator you use (simple of scientific). So which is ‘correct’?
Answer: 13
So with 3 + 5 x 2, the first thing to do is 5 x 2, then add the 3.
To make this easier we often put brackets round parts of the question, to make it clearer, like this:
3 + ( 5 x 2 )
Primary children might not be introduced to the term BODMAS but they should be working in the correct order.