This resource was inspired by the Puzzle of the Month in the always informative newsletter by Andrew Jeffrey, also on twitter as @AJMagicMessage. The challenge is to arrange the numbers 1 to 15 so that each adjacent pair, when added together, result in a square number. This puzzle is particularly nice in that it doesn’t need a high level of maths knowledge to engage with. Simple adding and identifying square numbers is all that is needed. Even this latter requirement is quite easy as there are very few square numbers that these numbers can result in. Despite this ease of engagement it will still provoke in depth thinking.

The puzzle is easily played using counters or sticky notes but to alleviate the danger of rogue gust of wind or sneezes this resource lets it be played or demonstrated on computer or tablet, either iPad or Android. This also makes it a nice homework puzzle to set.

Tapping the circles lets them switch places and their sums are automatically calculated in the squares above them. When a new square number is made a little burst of ticker tape confirms it. When all 14 are correct you’ll know!

For the solution you’ll need to see Andrew Jeffrey’s newsletter next month. If you miss that you’ll need to solve it yourself!

Go to Puzzle Resource

Note that you will need a modern browser to run this resource on your PC. IE10 or the latest version of Chrome or FireFox are recommended. On Android you should use Chrome not the basic Android Browser.