Pattern Rules Using Words and Numbers

A pattern rule is the mathematical description of a pattern. Once you know the rule, you can generate any term without listing all previous terms. Start at 4, add 7 each time: the 10th term is 4 + 9x7 = 67. This is genuine algebraic reasoning in Grade 3. The rule is a compact description of an infinite sequence. Students who can state a rule in words and use it to predict distant terms have taken the first step toward writing algebraic expressions.