Like its forerunners Sudoku and Kakuro, CalcuDoku is an addictive, easy-to-learn puzzle from Japan. Calcudoku are math-based puzzles with an element of logic.
Here are the rules: Each puzzle consists of a grid containing blocks surrounded by bold lines. The object is the fill all of the empty squares so that the numbers 1 to 5 appear exactly once in each row and column. The numbers in each block must produce the result shown in the top left corner of the block according to the math operation shown at the top of the grid.
