Cage combinations
Some cage totals can only be made one way. Learn the key ones.
Each cage’s numbers add up to its total, with no repeats. Some totals only have one combination: 3 in two cells is always 1+2, 4 is 1+3, 16 is 7+9 and 17 is 8+9. In three cells, 6 is always 1+2+3 and 24 is always 7+8+9.
Start with these unique cages: they tell you exactly which numbers are inside, even if you don’t yet know the order.
Medium cages often allow two or three combinations. Compare them with the numbers already used in the row, column or box to narrow them down.
Practise it
The Hint button on every puzzle explains the next step in the same plain language, so you can learn as you play. Play a Killer Sudoku puzzle.