# Advent calendar 2016

## 6 December

When you add up the digits of a number, the result is called the digital sum.

How many different digital sums do the numbers from 1 to 10

^{91}have?** There was a mistake in this question (it previously said 10

^{92}). If you answered the typo'd question right, your answer should automatically correct itself to 9 less than it was...