Dec. 20 Cover Image

Dec. 20 Math Mystery Year Puzzle: First International Human Solidarity Day

December 20 of the Mystery Year marks the first International Human Solidarity Day. Math clues for finding the year involve operations with decimals, working with percents greater than 100%, and multiplicative comparisons. Included is a simulation, The Distribution of Food in the World. Students learn that a key goal of International Human Solidarity Day is to eradicate poverty. This interesting puzzle provides mixed math review for middle school and high school students.

Your PDF download includes:

1-page printable student puzzle
2-page digital version with horizontal layout and larger print
4 pages of Teacher Notes including step-by-step solutions, historical notes, and more
1-page How to Use History-Mystery Puzzles