Description
The Chemical Calculator combines invisible ink with a sophisticated math trick. The audience is poled for digits to use in either a 2-digit or 3-digit set of calculations. Once the digits have been obtained, a difference is calculated between the original set of digits and the same digits in reverse order. That answer is added to a reversed version of itself. The chemical calculator is a solution in a spray bottle. When the spray bottle has had a chance to examine the problem, it contents are sprayed at the bottom of the sheet. The correct answer appears. A bit of art history is included in the explanation and teaching notes. Two additional, fun things to do with the ink are described. This activity can be adapted to allowing students to prepare and then develop their own hidden messages.
Publication Date
12-2025
Document Type
Book Chapter
Rights
© 2025 Garon C. Smith
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.
Recommended Citation
Smith, Garon C., "Chapter 5: The Chemical Calculator" (2025). G. Wiz’s Book of Spells. 7.
https://scholarworks.umt.edu/gwizchemistrymagic/7