2 + 11 - 1 = 12.
Figure 1 demonstrates a "proof with words"!
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.