Childrens understanding and use of inversion in arithmetic1

In this presentation, I consider the origins and the extent of children’s understanding of the inverse relation between addition and subtraction. I argue that this understanding might have its origins in children’s informal experiences with physical matter but I also show that it is possible to improve children’s grasp of inversion through teaching. I also show that his teaching has beneficial effects on children’s solutions to sophisticated word problems in which the arithmetical operation that is need for the solution is not immediately obvious