Explicit teaching — I Do (~15 min)
The goal is to move students from describing the step of a pattern ("add 3") to a general rule that links any position directly to its term.
1. Building patterns WA6MNAP1
Make a growing pattern with matchsticks: 1 square uses 4 sticks, 2 squares use 7, 3 squares use 10. Record position against count in a table.
2. Spotting the rule
3. Decreasing patterns
Guided practice — We Do (~20 min)
- Grow it together. Build a triangle-tile pattern as a class and fill the position/count table to 5 terms.
- Predict term 10. Use the rule to jump ahead without building, then verify by extending the pattern.
- Words to rule. Convert several verbal descriptions into a position rule, and rules back into words.
- Make a decreasing pattern. Pairs design one decreasing pattern, tabulate it, and write the rule in words.
Independent practice — You Do (~15 min)
Students complete the worksheet:
- continue three given patterns (two increasing, one decreasing) for three more terms;
- complete position/term tables;
- write the rule for each in words;
- use a rule to find the 10th and 20th terms without drawing.