Question

Find the product of the:
(i) greatest number of three digits and smallest number
of five digits.
(ii) greatest number of four digits and the greatest
number of three digits. [3 Marks]

Answer 1

(i) Greatest number of three digits = 999
Smallest number of five digits = 10000
Required product = 999 × 10000
= 9990000 [1 Mark]

(ii) Greatest number of four digits = 9999
Greatest number of three digits = 999
Required product = 9999 × 999
= 9999 × (1000 – 1)
= 9999 × 1000 – 9999 × 1
[Using distributivity] [1 Mark]
= (10000 – 1) × 1000 – (10000 – 1) × 1
= 10000000 – 1000 – 10000 + 1
= 10000001 – 11000
= 9989001 [1 Mark]