Grades

Grades is a logic puzzle. The goal is to place numbers in some cells of a square or rectangular grid according to the rules:

• No two horizontally, vertically or diagonally adjacent cells contain a digit.
• The numbers across the top and down the left equal the row and column totals for the cells with numbers.
• The numbers across the bottom and down the right are the sums of numbers in the rows and columns.

Cross+A can solve puzzles from 4 x 4 to 30 x 30.