Place two mirrors at an angle greater than 90 °. In the corner, place an apple.
Here begins, but is just beginning, a real miracle. Apples became three. And if you gradually reduce the angle between the mirrors, the number of apples begins to increase.
In other words, the smaller the angle of convergence of mirrors, the greater the impact objects.
Ask your child if you can make one apple 3, 5, 7, without using sharp objects. What did he say? Now put the above experience.