You may also like

problem icon

Number Detective

Follow the clues to find the mystery number.

problem icon

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?

problem icon

(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?

Reach 100

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Shannon, Ellie, Stephen, Tom and Zachary all at Trinity Middle School, Newport, Isle of Wight found solutions to "Reach 100". Shannon and Ellie realised that the numbers 12, 14, 27 and 47 total 100. Tom and Stephen each suggested a different way the digits could be arranged in the grid:
1 2
4 7
1 4
2 7
Zachary spotted both of these, and also sent this solution:
2 3
1 8
Kirsty, from St Aldhelms School in Poole, rearranged these digits to make this solution:
2 1
3 8

Lachlan and Ryan, from St Peter Julian Eymard Primary School in Australia, thought about what happened if the digits do not have to be different. They came up with this solution:
1 5
1 7

Can you think of any other examples if the digits are allowed to be the same?

Thank you and well done to everyone for sending in your solutions.