Sat, 28 May 2022
Just for Fun
Can you work out the word that fits this pattern?
New puzzle daily.

RA??BE???

How do subtraction and division work in calcudoku?

It can often be a little confusing to see how subtraction and division work in a calcudoku puzzle compared to ordinary killer sudoku.

The reason for this is that the order matters in the way it does not with addition or multiplication.

We know that 4 x 5 = 5 x 4 and that 4 + 5 = 5 + 4

However, we also know that 9/1 is not the same as 1/9, and similarly that 2 - 5 is not the same as 5 - 2.

The way this is tackled in calcudoku is to ensure that you always start with the largest number, and then subtract or divide the other number(s) from it.

Thus if you had 9 and 1 in a subtraction region, you would always perform the calculation 9 - 1 to get a total of 8-.

Interestingly some calcudoku puzzles (you may know these as kenken TM or hitoshii TM which are trademarks) only allow subtraction and division regions to be of size two. There is no actual reason for this as once you have set the rule that you simply subtract or divide from the largest number in the region then there is no reason not to have subtraction or division regions larger than this.

Most popular questions in puzzle category:

How do I solve calcudoku puzzles?
As with solving kakuro, the first few puzzles take longer...

What is calcudoku?
Calcudoku is a popular variant of killer sudoku. The key...

How do subtraction and division work in calcudoku?
It can often be a little confusing to see how subtraction...

Publishers:
View a list of puzzles for publication with pictures of each.

Individuals:
Play hundreds of puzzles for personal enjoyment online at the Puzzle Club
Large range of printable puzzles for personal use downloadable at Puzzle Magazine website.

Search Puzzle FAQ

Puzzle Solutions
i Newspaper Solutions

View a single page overview
list of puzzles

list of kids puzzles

Word Puzzles
Children's Puzzles
Wordsearch
CodeWords
Arrow words
Kriss Kross
Word Wheel

Number & Colouring Puzzles
Children's Sudoku
Samurai Sudoku
Jigsaw Sudoku
Futoshiki
Mind Games
Killer Sudoku
Kakuro
Chess Puzzles
A - Z of Puzzles
Colour By Number
Dot To Dot

Puzzle Tools
Puzzle FAQ
Codeword Solver
Rhyming Dictionary
Puzzle Solving Tools
Solving Videos

Services
Puzzles for Apps
Article Writing
Themed Puzzle Pages