Mathematical methods are used to study certain related Logo procedures in detail. Simple procedures with known properties are then used to build the higher-level procedures which correspond to higher-level mathematical concepts. Examples are from introductory aspects of number theory. (MNS)

An example is given of how to help students who have obtained a correct answer by a wrong method. They are asked to suppose that a child has found an easy method for division, and eventually write a computer program to show the correct method. (MNS)

Numerical inaccuracies, which occur in many ordinary computations, can create serious problems and render answers meaningless. Cancellation and accumulation errors are described, and suggestions for experimentation are discussed. (MNS)

The author presents two examples of lattice multiplication followed by a computer algorithm to perform this multiplication. The algorithm is given in psuedocode but could easily be given in Pascal. (PK)