Evaluating statements about number operation

This resource develops the concept of substitution of integers, fractions, decimals, and directed numbers into inequality statements in order to test their validity. Students also represent inequalities algebraically and in words.

An initial question that students work on is representing the statement

‘I subtract five from my number and my answer is less than four’

algebraically as

x ­– 5 < 4

In later work algebraic statements are given and students test them to establish conditions under which they are true. There is then an activity that involves completing and matching cards with inequalities represented in words, algebraically and with statements about restrictions on values that make the inequalities true.

There are pre-lesson and post-lesson formative assessment tasks. Detailed teacher notes give suggestions on questioning and how to use the resources. Full solutions are given for each of the sections.

This is a concept development lesson from the Mathematics Assessment Resource Service, a collaboration between UC Berkeley and the Shell Centre team at the University of Nottingham. Further information on the collection is given here.