Question

Check the divisibility of 21436587 by 9.
[2 marks]

Answer 1

As we know the number is divisible by 9 if sum of its digits is divisible by 9.
The sum of the digits of 21436587 is
2 + 1 + 4 + 3 + 6 + 5 + 8 + 7 = 36.
[1 mark]
This number is divisible by 9 as the sum of digits is divisible by 9.
i.e. 36 ÷ 9 = 4

Hence, 21436587 is divisible by 9
[1 mark]