San Francisco Math Circle. (2021). Mind Reading with Math. In S. Bowen (Ed.), Math Circle Activity Database. American Institute of Mathematics. https://mathcircles.org/activity/mind-reading

Mind Reading With Math

For the Math Mind Reading Trick, you’ll need a volunteer who’s willing to have their mind read. The person performing the trick holds out the four cards and askes their volunteer to pick a number (whole numbers only, no fractions allowed!) between 1 and 15 and keep it a secret. Next, the mind-reader asks the volunteer if their number is on the cards one-by-one. The volunteer answers the questions with yes or no answers, and with some magic and a little math, the mind-reader figures out their number!

Activity Handouts

Click on a handout to open in Google Drive or use the buttons below to download all handouts

Activity Guide

This guide looks at the activity in detail and goes into the underlying math.

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