Volume 1
Easy to Hard
Killer sudoku books: no digits to start
No digits to start: dotted cages with totals, solved by logic alone.
What is killer sudoku?
Killer sudoku, also called sum sudoku, starts with an empty grid. Dotted cages mark small groups of cells, and each cage shows the total of its cells. You place 1 to 9 so that every row, column and 3 by 3 box holds each digit once, and the digits in a cage add up to its total without repeating. Every puzzle has exactly one solution, checked by computer.
How to solve it
- 1Start with the small cages. A two-cell cage of 3 can only be 1 and 2.
- 2Remember that every row, column and box adds up to 45. A box with one cell outside its cages gives you that cell straight away.
- 3Write in what you know, then use the cage totals to narrow down the rest.
- 4The answers are at the back, with every digit printed.
Levels
What Easy, Medium and Hard mean here
As in all our sudoku, the level is the hardest method a puzzle needs.
Easy
Solved with cage totals and the 45 rule: what a small cage can be, and what a row, column or box adds up to.
Medium
The cage totals are not enough. You also need pairs and pointing.
Hard
Needs advanced methods, such as three cells sharing three digits. Still logic alone, never guessing.
The books
Killer Sudoku books
What is inside every book
- 100 puzzles, one to a page
- Dotted cages with their totals, and no starting digits
- Levels graded by the solving methods each puzzle needs
- Answers at the back, with every digit printed
- Every puzzle has exactly one solution, checked by computer
Questions
- Do I need to be good at sums?
- Only at adding small numbers. The cage totals are small, and the first steps are about which digits can make a total.
- Are killer sudoku harder than classic sudoku?
- They are different. With no starting digits it feels harder at first, but our Easy volumes need only the simplest steps.