NumSum: Number Sum Puzzle

1,000 hand-crafted stages plus 4x4 to 8x8 challenge mode. Built-in tutorial for newcomers. The relaxing math puzzle for commutes and quiet moments.

NumSum is a relaxing number puzzle with 1,000 hand-crafted stages. If you love Killer Sudoku, Kakuro, or any number-based logic puzzle, NumSum offers a fresh twist: eliminate cells so every row, column, and colored region sums to its target.

Easy to learn in 60 seconds. Deep enough for 1,000 stages.

PERFECT FOR

• Killer Sudoku, Kakuro, and KenKen fans
• Brain training enthusiasts
• Anyone who wants a quiet, focused puzzle game
• Commutes, lunch breaks, and quiet evenings
• Math puzzle and logic puzzle lovers

WHAT MAKES NUMSUM DIFFERENT

1,000 Hand-Crafted Stages Every stage is hand-tuned for a smooth difficulty curve — not auto-generated noise. The challenge grows with you over weeks, not minutes.

4x4 to 8x8 Challenge Mode For seasoned puzzle solvers. The 8x8 board is a 15-to-30-minute brain workout — the kind of puzzle you sit with a cup of coffee for.

Built-in Tutorial Worried about the rules? The interactive tutorial teaches you in 60 seconds. No external guides needed.

HOW TO PLAY

1. Each row and column has a target sum, shown on the top or left of the board.
2. Tap a cell in Pencil mode to circle the numbers you want to keep.
3. Tap a cell in Eraser mode to remove the numbers that don't belong.
4. When every row, column, and colored region matches its target, you win.

Colored regions act as a hint for which numbers naturally group together, especially on larger boards.

DESIGNED FOR FOCUS

• No countdown timer. No streak pressure. No flashy distractions.
• Subtle tap sounds and haptic feedback only.
• Fully offline — play on flights, trains, or anywhere without Wi-Fi.
• Lightweight battery and data footprint.
• Available in English and Japanese.

ABOUT THE ADS

NumSum is free to play with light ads to support development:

• A banner ad below the game board
• An optional rewarded ad shown between stages

We never force ad views to progress. Focus comes first.

UPDATED REGULARLY

We add new stages every month based on player feedback. Drop us a review with your ideas.

ABOUT THE DEVELOPER

AKG LLC (合同会社AKG), based in Tokyo, Japan. A small studio crafting calm, focused puzzle experiences. We made NumSum because we wanted a Killer Sudoku-style puzzle that's faster to pick up but just as rewarding to master.

SUPPORT

Email: araki@akg-inc.net Privacy Policy: https://www.akg-inc.net/numsum/privacy.html

Whether you call them sum puzzles, math games, brain teasers, or simply your daily focus ritual — we hope NumSum becomes a small, satisfying part of your day.

Sharpen your mind. One puzzle at a time.

Keywords: number puzzle, math puzzle, brain training, brain teaser, logic puzzle, sum puzzle, math game, brain game, mental math, offline puzzle, relaxing puzzle, single player puzzle, casual puzzle, brain workout, kakuro, killer sudoku style.