Review question

# What do we get if we add the digits of the integers from 1 to 99? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R7399

## Suggestion

The function $S(n)$ is defined for positive integers $n$ by $S(n) = \text{sum of the digits of }n.$ For example, $S(723) = 7+2+3=12$. The sum $S(1) + S(2) + S(3) + \dots + S(99)$ equals

1. $746$,

2. $862$,

3. $900$,

4. $924$.

Could we lay out the $S$ values in a table?

How often does the digit $1$ appear in the numbers from $1$ to $99$?