Discusses play and play centers for children. (Editor)

Activities are described that involve polyhedrons constructed with a marble inside enabling them to roll across a smooth surface. Directions are given for constructing such a tetrahedron. (DT)

Lists of materials for a mathematics laboratory and some suggestions for activities are given. (DT)

Patterns for a set of Napiers Bones and for a denominate number slide rule are provided, with instructions on how to use each of the calculating instruments. (DT)

This article shows how simple instruments may be used to construct angles of certain measures and applies this procedure to more detailed problems. A proof of the Pythagorean Theorem is given using these procedures. (CT)

Children were pretested and assigned to one of three treatments: training with three dimensional manipulanda; the same program except that the instructional materials were line drawings; and a control. On the posttest, both experimental groups were significantly superior to control group. (Author)

The importance of having children manipulate small objects that can be grouped, arranged, and counted is discussed. Learning activities for one-to-one correspondence, numerals, and the four operations are given. (MNS)

Using squared paper as a concrete aid, children can explore important concepts about the perimeter and area of geometric figures. Activities are described and illustrated to develop several methods of finding perimeter and area. (MNS)