Practise: Cage elimination
This Killer puzzle stalls at exactly the point where Cage elimination is needed. Work it out yourself, or jump straight to that position.
Skip the obvious cells and start where the technique matters.
Your turn first
Spot the idea before the hint explains it
- 1. Look
- 2. Check
- 3. Proof
Look at the marked starting cell, cage outline and sum. Which digit or combination is forced, and what visible sum fact supports your idea?
How to spot it
Look at cages of three or four cells whose sum is well away from the middle of the range. Then check which digits appear in none of the remaining combinations.
Put it to use
Where you will meet it
Hard grids are built around moves like this one. That is where it earns its keep.
Play HardStuck on a grid of your own?
Type the position into the solver and it walks the whole solution, naming the technique behind every step — including this one.
Open the solver