2 + 11 – 1 = 12.
Figure 1 demonstrates a “proof with words”!
Presentation Suggestions:
Write the letters for two and eleven side by side, then cross out the letters for one as you say them.
The Math Behind the Fact:
This short fun fact does not really involve any mathematics, but it is rather amusing. After this see also Proofs Without Words.
How to Cite this Page:
Su, Francis E., et al. “Proof with Words.” Math Fun Facts. <https://www.math.hmc.edu/funfacts>.
Fun Fact suggested by:
Arthur Benjamin