Brackets

 

Brackets are used in a calculation to avoid confusion. When we need to carry out more than one number operation in an expression, we follow the BODMAS rule. It allows us to write out the calculation and arrive at the correct answer in a systematic manner.

 

Demonstration:

  • 6 × 109 = 6 × (100 + 9) = 6 × 100 + 7 × 9 = 600 + 63 = 763
 
  • 102 × 103 = (100 + 2) × (100 + 3) = (100 + 2) × 100 + (100 + 2) × 3

= 100 × 100 + 2 × 100 + 100 × 3 + 2 × 3

= 10,000 + 200 + 300 + 6 = 10,000 + 500 + 6

= 10,506

 

  • 17 × 109 = (10 + 7) × 109 = 10 × 109 + 7 × 109

= 10 × (100 + 9) + 7 × (100 + 9)

= 10 × 100 + 10 × 9 + 7 × 100 + 7 × 9

= 1000 + 90 + 700 + 63 = 1,790 + 63

= 1,853