Log in
Home Page
Mathematics
Read the In Focus question carefully.
What is it asking?
How will you work it out?
If we know that 10 × 9 = 90
9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 + 9 = 90
Then we can work out 9 x 9 = 81 by working out 10 x 9 first.
What is the difference between 10 x 9 and 9 x 9?
(10 x 9 - 9)
90 - 9 = 81
When working out 8 x 9
We can use our knowledge of 10 x 9 = 90
Then we can subtract 2 x 9 from 10 x 9 to work out the answer for 8 x 9
10 x 9 = 90
- 2 x 9 = 18
8 x 9 = 72