Question

9. Using the most convenient grouping, find each of the following products.
(i) 5 x 648 x 20​

Answer 1

(5 x 20)x 600 + 40 + 8
=(100 x 600) + (100 x 40) + (100 x 8)
= 60000 + 4000 + 800
= 64800

Answer 2

5×(648×20)=5×12960

=64800