Skip to content # Mind Reading With Math

## 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.

## Photos & Videos

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

Math Circles: JRMF, San Francisco Math Circle

- Activity Description
- Topics Covered
- Session Styles
- Mathematical Practices

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!