Kendoku CalcuDoku: 250 Medium to Hard 8x8 Square Wisdom Puzzles, Book 25, (Paperback)

CalcuDoku is a mathematical and logical puzzle loosely similar to Sudoku. The objective is to fill the grid in with the digits 1 through 8 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 which achieve the specified result using the specified mathematical operation: addition (+), subtraction (-), multiplication (×), and division (