Choose any three by three square of dates on a calendar page...
Can you explain how this card trick works?
Take any whole number between 1 and 999, add the squares of the
digits to get a new number. Make some conjectures about what
happens in general.
The digits in this multiplication have been reversed, and the
answer has stayed the same!
Is this surprising? Can you find other examples where this
What do you notice about the pairs of two digit numbers that
produce this special result?