Patterns with Words, Numbers, Symbols, and Variables
Warm-up
Show the pattern 3, 7, 11, 15. Rule in words: start at 3, add 4. Can I write this shorter? Term n = 4n - 1. Check: n=1: 4-1=3. n=2: 8-1=7. n=3: 12-1=11. Yes! Now: what is term 25? 4x25-1=99. Immediate, no listing required.
Explore
Pattern rule challenge: each group receives a table of values with 5 rows. They must: (1) identify the constant difference, (2) find the variable rule (term = ?n + ?), (3) verify with 3 term numbers, (4) find term 15, (5) find which term has value 100 (set up and solve the equation).
Consolidate
Practice
Students find rules for 4 tables of values, use each rule to find term 10, and solve for the term number that gives a specified value. Exit ticket: what is term 12 in the pattern with rule 4n + 5?
Exit ticket
Students find rules for 4 tables of values, use each rule to find term 10, and solve for the term number that gives a specified value. Exit ticket: what is term 12 in the pattern with rule 4n + 5?
Constant difference: 3. Rule: 3n + b. Substituting n=1: 3(1)+b=6, b=3. Rule: term n = 3n+3 = 3(n+1). Verify: n=2: 3x2+3=9. n=4: 3x4+3=15. Correct.
3n+3=21. 3n=18. n=6. The 6th term is 21. Check: 3x6+3=21. Correct.