In the first experiment, observations were made of children ages four-and-a-half to five-and-a-half years of age who were induced to use counting or matching in a Piagetian number conservation task. The spontaneous matching and counting behavior of a more mature but not yet conserving sample was investigated in the second experiment. (RH)

A computer program that allows students to simulate an experiment in probability is given, with specific suggestions on how to use and study the program. (MNS)

The "positive-negative charge" model is described and demonstrated with all four operations on integers. Its major advantages are that it is both concrete and complete. (MNS)

The article describes a diagnostic procedure for assessing children's mental images and knowledge of cardinal numbers, 0 through 9. The diagnostic procedure includes the assessment of a child's visual memory, visual perception, symbol recognition, oral naming of numerals, and symbol-set linkage. (Author/SBH)

This investigation concerns the repeated application of the rule "take the sum of the squares of the digits." (MP)

An illustrated score sheet is included in this discussion of a method of teaching number typing using number drill sheets for six minutes of each class period. (TA)

Reports three experiments which examined kindergarteners' ability to conserve number in response to three forms of questioning: nonverbal, standard, and control. There was no indication that a full mastery of conservation could be elicited earlier by the nonverbal procedure. (Author/JMB)