Calcudoku Calcudoku: 200 Hard Puzzles 6x6 vol. 7, Book 7, (Paperback)

Calcudoku (also known as "Mathdoku") is a mathematical and logicalpuzzle loosely similar to Sudoku.
The objective is to fill the grid in with the digits 1 through N (where N isthe number of rows or columns in the grid) such that:
- Each row contains exactly one of each digit.
- Each column contains exactly one of each digit.
- Each bold-outlined group of cells (block) contains digits whichachieve the specified result using the specified mathematical operation: addition (+), subtraction (-), multiplication (×), and division (