Sliding Puzzles
Sliding numbered blocks in a square grid to put them back in numerical order.
Colour Sorting Game
Constructing an unsolvable setup in a colour sorting game.
Re-Sorting
A problem about sorting a shuffled set of cards back into the original order
Connect Four
A question about arrangement of coloured chips on a Connect Four board
Splitting LCM
Four problems about splitting a natural number into smaller natural numbers.