Fill the empty white squares with numbers 1 through 9.
Sum Logic: The dark numbered blocks are clues. The white squares below a clue must add up to that number. Squares to the right of a clue must add up to the horizontal clue.
No Repeats: You cannot use the same number twice in any single sum (run). For example, a target of 4 must be [1, 3]. It cannot be [2, 2].
What is "Notes" mode?
When you toggle Notes: On (or press 'N'), tapping a number acts like making small pencil marks in the corner of a square. Use notes to keep track of possible candidates without committing to a final answer.
