# Count On

## Explorer

#### Puzzle of the Day

These puzzles are also printed in Eight days a week, a booklet published by the Association of Teachers of Mathematics.

Write two two-digit numbers whose digits add up to the same number. For example 56 and 29 (digits add up to 11) now take one from the other and add the digits of the answer. Do several pairs. What do you notice?

Answer: always add up to 9