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The Handshake Puzzle

Act out handshakes with friends and discover the pattern behind counting pairs.

Grade 4Math OlympiadMath ChallengeMathLogicNumber SenseBeginner30 to 45 min4 materials

What you'll learn

  • Count pairs without counting anything twice
  • Record results in a table and spot a pattern
  • Use the pattern to predict a bigger case without acting it out

Objective

Find a rule for how many handshakes happen when everyone in a group shakes hands with everyone else once.

STEM concepts

PatternsSystematic countingProblem solving
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Materials and safety
Step-by-step instructions
Prediction, test sheet and results
Why does it work, challenge and project report

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