Jan. 20 Cover Image

Jan. 20 Math Mystery Year Puzzle: Joan Kroc Gifts $1.6B to the Salvation Army

On January 20 of the Mystery Year, Joan Kroc gave a large charitable contribution to the Salvation Army. Clues for finding the year involve measurement conversions based on the magnitude of large numbers, simple interest, and expressing numbers in the form of a single digit times an integer power of 10. A printable Extension activity deals with the wealth distribution.

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 Extension: Wealth Distribution