Number Detective

Follow the clues to find the mystery number.

Six Is the Sum

What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?

(w)holy Numbers

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?

Four-digit Targets

Stage: 2 Challenge Level:

Try using cards numbered from $0$ to $9$ or even pieces of torn paper.
Where is the best place to put $9$ when you are aiming for the lowest number?
Where is the best place to put $9$ when you are aiming for the highest number?