This warm-up puzzle for middle school has math clues involving unit rate, probability, area of the remaining portion of a circle when an inner concentric circle is removed, greatest common factor, and least common multiple. The context is finding the Mystery Year that 7-in. 45 RPM records were announced.
Your PDF download includes:
- 1-page printable student puzzle
- 2-page digital version with horizontal layout and larger print
- 5 pages of Teacher Notes including step-by-step solutions, historical notes, and more
- 1-page How to Use History-Mystery Puzzles