Math with Bad DrawingsCartoon Archive

Parentheses Puzzle

January 2, 2017

A puzzle: insert parentheses into 1 + 2 × 3 + 4 × 5 + 6 × 7 + 8 to get as many different totals as possible, with worked examples.

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Free for classrooms, worksheets, slides and other non-commercial use under CC BY-NC 4.0, with credit to Ben Orlin.

Cartoon by Ben Orlin, Math with Bad Drawings. https://cartoons.mathwithbaddrawings.com/2017-01-02-parentheses-puzzle/ (CC BY-NC 4.0)
Transcript

"How many totals can you achieve, just by adding parentheses?"

1 + 2 × 3 + 4 × 5 + 6 × 7 + 8

[for example...] (1+2)×3+4×5+6×7+8; 1+2×(3+4)×5+6×7+8; 1+2×3+4×(5+6)×7+8; (1+2×3+4×5+6)×7+8; (1+2×3+4×5+6)×(7+8); 1+2×(3+4)×(5+6)×7+8; (1+2×3+4)×5+6×7+8; 1+2×3+4×(5+6×7+8); (1+2×3+4)×(5+6×7+8) etc.!

Topics
Number & Arithmetic › Order of OperationsNumber & Arithmetic › MultiplicationNumber & Arithmetic › AdditionMath Culture › Problem SolvingDiscrete Math › Combinatorics
Level
ElementaryMiddle SchoolHigh School
Themes
Visual ExplanationsPuzzles & Problems