This is one of a series of monographs developed by teachers in elementary schools near Leeds, England. This document focuses on structure and place value. Slow learners in particular need concrete experiences designed to introduce and later consolidate the idea of place value, and with this in mind several activities proven successful with slow learners are presented. In the section on structure of number, children are introduced to the basic idea of grouping in tens using materials whose physical properties determine their value. In the other section, the true idea of place value is demonstrated--value now depends not upon any physical property of the materials but entirely upon the position in which counters, beads, and later, numerals are placed. (MNS)