Add-In Circle Puzzles 1-3

This logical addition puzzle was designed to teach children strategy and to think “out-side the box”. In this case the box is round. The goal is to discover the center number by adding the four numbers that surround the center circle, but to determine those four numbers it is easier to start near the outermost rings and fill in empty slots where you know two or three of the numbers already. There is no guessing to these puzzles. All of them can be sorted through logically and methodically. I estimate each of these puzzles can be completed in 10 minutes or less. Have fun.

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Easy as LITS

Easy as LITS 1

It’s a mashup of Easy as ABC and regionless LITS.

Standard regionless LITS rules:

  • The shaded area must be continuous
  • There can’t be any 2×2 blocks of shaded cells
  • The shaded area must be tileable with LITS tetrominoes such that no two tetrominoes of same shape touch


  • No row or column may have two tetrominoes of the same shape in it
  • The clues along the edges tell the shape of the tetromino that is first seen in that column or row
  • (L and J tetrominoes and S and Z tetrominoes aren’t distinguished)
  • A bolded line between clue cells means the two cells can’t see the same tetromino
  • No line between clue cells means the two cells see the same tetromino
  • A dashed line between clue cells means the two cells may see the same tetromino, but not necessarily

Hopefully I was clear with the rules.