Using a piece of chalk, draw a hopscotch grid on the pavement mimicking a calculator layout. In one game ask which number is less than 4 or a 6. The child jumps on their answer. If they are not correct, go over the order of numbers and help them to learn that 4 is less than 6.
In another game give them a simple operation (e.g. 2+3, 5–0). Kids should take turns hopping on each element of the equation in the correct order, landing finally on the answer.