### Consecutive Numbers

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

### Calendar Capers

Choose any three by three square of dates on a calendar page...

### Building Tetrahedra

Can you make a tetrahedron whose faces all have the same perimeter?

Can you find distinct positive whole numbers $a$, $b$ and $c$ such that $a^2+b^2+c^2 = 11^2$?