Examples are presented in which students are able to answer test items requiring manipulation of numbers for such topics as reducing fractions, but lack understanding of the operation. In addition to paper-and-pencil test, interviews are recommended for evaluating a student's understanding. (JP)

Numbers drill as an approach to the introduction of language instruction. (RS)

Using negative digits in writing numerals and in calculation is explained. This is the second article in the series; for the first, see Vol. 1, No. 7, Nov., 1972, pp. 8-9. (DT)

The Shepherd's Principle (to count the number of sheep in a field, count the number of legs and divide by four) is applied to the problem of finding the number of different rectangles on an N by N checkerboard. (MM)

A method of generating a number sequence is defined, then those integers generating a sequence of period one are defined as happy.'' The properties of these sequences are investigated. A computer program is included. (DT)

A test of the relative effects of verbal definitions and numerical examples as correctional feedback in a computer-assisted learning task. (MM)