When we divide, we're rarely interested in what's left over. In these problems and games, we invite you to take a closer look at remainders and learn about Modular Arithmetic, an important area of Number Theory.
Frances and Rishi were given a bag of lollies. They shared them out evenly and had one left over. But when they shared them with more friends, there were two left over...
Play with our interactive machine and see if you can work out how to switch each light on. Is there a way to turn on all four lights at once?
Can you find rules for turning on pairs of lights, or even three or four lights?
In the video, Caroline and James pick sets of five numbers. Charlie chooses three of them that add together to make a multiple of three. Can you figure out a way they could stop him?