Why must 2 digits of any 2-digit number that is multiple of 9 (eg 27) add up to 9?
In: 0
Because 9 is a power of 3, and as such carries some of the properties of 3, such as the digits of a product of 9 adding up to a number divisible by 9
Why must 2 digits of any 2-digit number that is multiple of 9 (eg 27) add up to 9?
Latest Answers