Follow the clues to find the mystery number.
What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?
A church hymn book contains 700 hymns. The numbers of the hymns are displayed by combining special small single-digit boards. What is the minimum number of small boards that is needed?
This problem is based on a game published by BEAM as one of their Maths of the Months activities. You can play it as a game against a friend using this sheet from BEAM.