Principles for the teaching of mathematics must address several concepts. These include the child’s ability to understand number and number relations, which depends on mental development, that children acquire this ability at different ages and need varying amounts of practice in order to develop it, and that the prerequisite of sensorial foundations is in place.

Once this is determined, our math system of instruction includes learning by experiment, thought, and words, the use of concrete materials until the child abandons them, and a very clear presentation of the decimal principle on which our number system rests.