Sometimes you will see a calculation written in the form  \({\text{8 - (2 x 3)}}\) , where brackets, that is the symbols \((\) and \()\), are put around part of the calculation.
Brackets are  there to tell you to carry out the calculation inside them first. So  \({\text{8  - (2x3 )  =  8 -  6  =  2}}\).
If you had to find the answer to \({\text{8 }} + {\text{ 5 }} - {\text{ 3}}\) , you might wonder whether to do the addition first or  the subtraction first.
If you do the addition first,  \({\text{8 }} + {\text{ 5}} - {\text{ 3 }} = {\text{ 13}} - {\text{ 3 }} = {\text{ 1}}0\).

If you do the subtraction first,  \({\text{8 }} + {\text{ 5}} - {\text{ 3 }} = {\text{ 8 }} + {\text{ 2 }} = {\text{ 1}}0\) .

In this case, it makes no any difference which operation you do first.

If, however, you had to find the answer to  \({\text{3 }} + {\text{ 4x2}}\) , your answer will depend on whether you do the  addition first or the multiplication first.
If you do the addition first,  \({\text{3 }} + {\text{ 4x 2 }} = {\text{ 7x 2 }} = {\text{ 14}}\).

If you do the multiplication first,  \({\text{3 }} + {\text{ 4x 2 }} = {\text{ 3 }} + {\text{ 8 }} = {\text{ 11}}\).

To avoid confusion, mathematicians have decided that, if there are no brackets, multiplication and  division are carried out before addition and subtraction.

Such a rule is called a convention: clearly the opposite decision  could be  made,  but  it  has  been  agreed  that the  calculation \({\text{3 }} + {\text{ 4x 2}}\)  should be carried out as  \({\text{3 }} + {\text{ 4x 2 }} = {\text{ 3 }} + {\text{ 8 }} = {\text{ 11}}\).

There are  a  number of these conventions, often  remembered by  the word 'BoDMAS', which stands for:

• Brackets
• Divide
• Multiply
• Add
• Subtract

This  is  the order  in  which arithmetic operations must be carried out.
Most  calculators  have  the  'BoDMAS '  convention  programmed into them, and so automatically carry out operations in the correct order.

Below you can download some free math worksheets and practice.