Problems involving divisibility, the ten coin triangle, five times a week with 4 D, a nomogram for the lens formula, the box and ladder problem, chains of circles, tessellating hexagons, topological woggles, and numbers of triangles are discussed. (CT)

This article displays the graphs of number patterns obtained by writing each number in the pattern as an ordered pair, plotting the ordered pairs, and joining consecutive points by straight lines. (DT)

This article describes how the arrival rate and service time distribution of a queue were investigated, and how a subsequent random-number simulation of the queue was carried out. (MM)

A proof is given that for any four digit number, repeated reordering of digits and subtraction will evenutally result in the number 6174. A computer program is included. (DT)

A new approach to classifying quadrilaterals is presented that tries to classify all possible combinations of shapes and angles by removing the traditional Euclidean viewpoints. The document concludes with a brief look at other types of polygons. (MP)

Materials for sorting, counting, and number activities are listed, with sources. This is the third of a series in a revision of a materials list given in issue No. 40; earlier lists in the revision appeared in issues No. 58 and 59. (DT)