Sumbox: Arithmetic Puzzle

Sumbox is a cage-arithmetic logic puzzle in the spirit of KenKen. Fill every row and column with 1 through the grid size, each number appearing exactly once. The grid is also divided into outlined cages, each showing a target number and an operation. The values inside a cage must add, subtract, multiply, or divide together to reach that target — no guessing required, just deduction. There is no ambiguity. Each of the 150 puzzles has been checked by a real solver to guarantee a single, logical filling — a path of pure deduction always exists from the first cell to the last. FEATURES • 150 hand-verified puzzles across three grids – Basics (4×4), Balance (5×5), Overdrive (6×6) • Guaranteed unique solution on every board — solvable by logic alone • Simple tap-and-type controls: select a cell, enter its value • Live conflict detection across rows, columns, and cages • Earn up to three stars per puzzle for efficient solving • Cool blueprint-inspired visuals with cyan cage clues • Calm ambient soundtrack and tactile feedback — both toggleable • Fully offline. No ads, no accounts, no tracking. Progress stays on your device. Balance every cage.