Basic Operations

L.O – To recall the concept of BIDMAS and recognise its importance in calculations

BIDMAS tells us the order that we carry out calculations

This tells us that any brackets need to be dealt with first, followed by indices (i.e. powers), then division, multiplication, addition and finally subtraction. It is essential to carry out the calculation in this order, otherwise the answer calculated will be incorrect.

Example 1:

Calculate 3 + 7 x 10 – 2

• Remember BIDMAS
• There are no brackets, indices or divisions in this calculation, so the first operation to deal with is multiplication

3 + 7 x 10 – 2

3 + 70 – 2

• Next, we need to deal with the addition

3 + 70 – 2

73 – 2

• The last operation is subtraction

73 – 2 = 71

Example 2:

Calculate 50 – 6²

• Remember BIDMAS
• BIDMAS tells us indices come before subtraction

50 –  6²

50 – 36

• Next, carry out the subtraction

50 – 36 = 14

Example 3:

Calculate (1 + 4)² x 3 – 25

• Remember BIDMAS
• BIDMAS tells us brackets come first

(1 + 4)² x 3 – 25

5² x 3  – 25

• Next, we need to deal with the indices

5² x 3 – 25

25 x 3 – 25

• According to BIDMAS, multiplication comes next

25 x 3 – 25

125 – 25

• Finally, deal with the subtraction

125 – 25 = 100