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.