Number puzzles
Write digits into cells so that sums, products and comparisons all come out right. Kakuro is a crossword of sums, KenKen adds arithmetic cages to a Latin square and Futoshiki replaces most givens with greater-than signs. All three reward the same habit: work out which digits are possible before you write anything.
All number puzzles
What makes a number puzzle
Every puzzle on this page ends with a grid full of digits, and every one forbids repeats along a line. Kakuro runs must add up to their clue with no digit used twice. KenKen and Futoshiki are Latin squares, so each row and column holds 1 to N exactly once, with cage arithmetic or inequality signs as the extra constraint. Sudoku, coming soon, adds boxes on top of the rows and columns.
The shared technique is candidate elimination: list the digits a cell could hold, then strike out the ones a sum, a sign or a neighbour rules out. Pencil marks make this painless. Start with a 5×5 Futoshiki, then a 4×4 KenKen, and save the 10×10 Kakuro for when the unique-combination sums are second nature.
FAQ
A 5×5 Futoshiki. The signs give quick deductions and the Latin-square logic is the same as Sudoku. KenKen adds arithmetic, and Kakuro is the deepest of the three.
Never inside one run. The same digit may appear in two different runs that cross, which is exactly what makes crossing clues so useful.
No. Every grid here is verified to have a single solution reachable by logic. If you are stuck, use Check to see whether the digits you have entered are still consistent.