Grade 5 · Algebra · Patterns and Equations
Find the Rule and the Unknown
Patterns help us predict values we have not built yet. Variables let one rule work for every term.
The big idea
A rule connects the term number to the term value
If a design begins with 2 tiles and gains 3 tiles each term, its values are 5, 8, 11, 14. The rule 3n + 2 describes every term.
Work it through
Find term 10 for the rule 3n + 2
- 1. Replace n with the term number: 3(10) + 2.
- 2. Multiply first: 30 + 2.
- 3. Add: term 10 has 32 tiles.
- 4. Verify that moving from term 9 to term 10 adds 3.