Game Strategy: In a number game, you score points equal to
2n + 1, where n is your roll. If
you need exactly 15 points to win, what must you
roll?
Strategy: Set up the equation 2n + 1 = 15
and solve for n.
Explain your solution:
Sentence frame: "I solved 2n + 1 = 15. Subtracting 1 gives 2n = ___.
Dividing by 2 gives n = ___."
✓Correct! 2n + 1 = 15 → 2n = 14 → n = 7. You need to roll
a 7!
✗2n + 1 = 15 → 2n = 14 → n = 7 (C).
★
Challenge
1 question
Challenge
Double Puzzle: I am thinking of two consecutive whole numbers. The sum
of the smaller number and twice the larger number is
17. What are the two numbers?
Strategy: Let the smaller number be n. The
larger is n + 1. Write the equation: n + 2(n
+ 1) = 17.
Smaller number:
Larger number:
Show your algebraic reasoning:
Sentence frame: "I let the smaller number be n. The equation is n +
2(n + 1) = 17. Simplifying: ___ = 17, so n = ___. The numbers are
___ and ___."
✓Correct! n + 2(n + 1) = 17 → 3n + 2 = 17 → 3n = 15 →
n = 5. The numbers are 5 and 6.
✗n + 2(n+1) = 17 → 3n + 2 = 17 → n = 5. The numbers are
5 and 6.