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.

			10	17	28			15	9
		24 18					8 10
	17 4					19 11
8				21				12	6
12			20	10 16			4 19
		12			17
	13	15 21			10 26			31
16						10			11
29						27	7
4			10				9 27
7			11	35
	8			18 15
	9	12 13			12
10					16 30			9	15
15			12 17				11
	9	17 16				9	7 4
22				24
11				9

Free online kakuro puzzles