About Number Sums: A Challenging Mental Math Puzzle

Number Sums is a number puzzle built to train mental math and sharpen logic. The goal is straightforward to state but demanding to execute: every row, every column, and every colored region on the board must sum to the clue values shown on the sides of the board and inside each region. All of those constraints must be satisfied simultaneously, which is what gives the game its real bite.

Boards range from 3×3 up to 10×10, and each level carries only one valid solution. The mechanics of these math riddles sound simple but require sustained thinking, making Number Sums a solid workout for addition skills and everyday arithmetic.

How to Play Number Sums

The board presents numbers arranged in rows, columns, and colored regions. Each of those groupings has a target sum displayed as a clue. The task is to identify exactly which numbers belong and which are surplus, so that every row, column, and region hits its target at the same time.

Circling and Erasing

• Circle correct numbers: select the numbers that add up to the clue values for their row, column, and colored region.
• Erase unwanted numbers: mark the numbers you don't need so they are excluded from the sums.
• Toggle between modes: use the toggle to switch between circling mode and erasing mode, helping you keep track of which numbers are confirmed and which are ruled out.

Board Sizes and Difficulty

• Boards open from 3×3 up to 10×10.
• Various levels of difficulty are available across the puzzle set.
• Every level has exactly one possible solution, so rows, columns, and colored regions must all work together at the same time.

Games You Might Like

If number logic keeps you coming back, Sudoku offers a classic grid challenge where every digit from 1 to 9 must appear exactly once in each row, column, and 3×3 square — a natural companion to Number Sums for fans of constraint-based puzzles. For something with a matching twist, Number Match - Classic number game has players hunting for identical pairs or pairs that sum to 10, making it another strong pick for daily arithmetic brain training.

Browse the full educational games collection for more math and logic titles, or explore the wider puzzle games library for hours of number-based challenges.