Class 3 took to the sunshine again this week to investigate how many moves it would take to swap two families of ‘frogs’ who were on opposite sides of a pond and trying to cross on lily pads. We all managed to complete the puzzle with three ‘frogs’ in each family. Some of us went on to manage with four ‘frogs’ in each family. After break we carried on in the classroom with five per family. We then looked at the pattern of the number of frogs in each family and the smallest number of moves that could be used to swap them over. Some of us managed to work this out and came up with a formula to predict the minimum number of moves for other potential numbers of frogs in each family.