# Opdoku = Calcudoku + Mathdoku 4+

• Free

## Description

M.: »Absolutely love this app - simple easy to use interface and free.«

Opdoku is completely free of charge, with no adverts or additional purchases. Sounds good? Try it out today! The rules are simple:

○ As in Sudoku, each digit can only appear once in each row and column.

○ Each digit is part of a group, each of which has a mathematical operation and a result. All digits in the group have to achieve the specified result using this mathematical operation.

Your task is to enter the digits in the grid so that both of these rules are met. Sounds easy? Give it a try!

Opdoku is similar to Mathdoku, but with three improvements:

○ If you wish, the puzzle can also have two additional mathematical operations – minimum and maximum. This makes the game more varied and diverse.

○ You can solve puzzles in which only the result of a group is known, but not the mathematical operation. How is 4 reached? Is it 1 + 3, 1 x 4 or 4 / 1? Anything is possible! Hint – 1 is always present.

○ You can even solve puzzles in which not all results of the groups are known. Only geniuses need apply!

All Opdoku puzzles have a unique solution. As they are generated automatically a virtually infinite number of puzzles are available. These range from easy ones on a 3x3 grid to virtually impossible ones with barely any clues on a 6x6 grid.

## What’s New

Version 5.1

Added a new option that determines whether possible combinations are displayed.

## Ratings and Reviews

3.9 out of 5
9 Ratings

9 Ratings

Dash600 ,

### Best Kenken app I’ve found.

There are no advertisements, they’re not hounding you for money, and the implementation of the puzzles is great. It’s a breath of fresh air.

Nottartsydoc ,

### Missing Features

I love the variety of modes in this game. I would like to have a way to mark possibilities on each tile as opposed to only one number. I also want to be able to highlight all numbers on the board of a specific value to make it easier to see what to do next. This will be especially useful for harder puzzles. I am willing to pay a one time price for these additional features.
Edited: There has not been any updates since the developer's response.

### Developer Response ,

Ui, only 2 stars…? But, ok, thank you for your feedback.
I will try to add the features you asked, I had them already programmed, but - at least for me - the game became a bit too ‚mechanical‘ then. I will try it again!

Janiebirdnc ,

Very fun.