Kakuro

Language:

4x4: easy intermediate hard challenging expert
6x6: easy intermediate hard challenging expert
8x8: easy intermediate hard challenging expert
9x11: easy intermediate hard challenging expert
9x17: easy intermediate hard challenging expert

Kakuro is like a crossword puzzle with numbers. Each "word" must add up to the number provided in the clue above it or to the left. Words can only use the numbers 1 through 9, and a given number can only be used once in a word. Every kakuro puzzle has one and only solution, and can be solved through logic alone.

Kakuro Blog
Kakuro Rules
Kakuro Tutorials: Basic Challenging

Kakuro Hint: Start with clues that only have one valid combination. For example, 3 in 2 must be 1 and 2, and 23 in 3 must be 6, 8, and 9.

			17	40	9	12	37
	16	32 17
31								24	11
29					24
	7	11 42			25	14
34						10 29
7			30					40
5			28 15						5
	11 16			6 30			6 3
29					20 15
15			13 41			3 41			10
	20						4
	10	19 24					10 18
17				30
10				14	12			3	9
24					26 10
		28
		32

Free online kakuro puzzles