About Sum Grid
In the registrar’s warded counting room, every row and column is an account. Each numbered tile starts included. Cross out the entries that do not belong until the numbers left behind match the targets at the edge of the ledger.
A tap cycles a number through included, crossed out and a kept note. The clue shows its current total over its target, and a balanced line seals with blue-gold light. Undo and Restart let you reconsider without losing your place; there is no failure timer.
All 180 fixed ledgers are open from the start, in four shelves from 4×4 to 7×7. Each has one independently verified solution and can be reasoned out without guessing. Your first solve time stays on the board, with the verified public best and its holder beside each ledger and in the game page trophy.
How to play
- Goal
- Cross out numbers until the remaining numbers in every row and column add to their shown targets.
- How it ends
- A board is won when all row and column sums match; there is no loss, and marks can always be changed.
- Record
- Your first solve time is kept for each board, and the fastest verified first solve appears beside the board and in the page trophy.
- The number beside each row or above each column is its target. The current sum is shown above the target.
- Click or tap a number once to cross it out; crossed numbers no longer count. Tap again to mark it kept, then again to clear the note. Kept notes are optional.
- Balance every row and column to finish. The clock starts when a ledger opens and keeps running through a restart or return to the shelf.
Controls
| Tap / click | Cycle a tile: included, crossed out, kept note |
|---|---|
| Right click | Cycle the other way |
| Arrow keys | Move between cells |
| Space / Enter | Cycle the focused tile |
| X / K / Delete | Cross out, mark kept, or clear the focused tile |
| Z / Escape | Undo or return to the shelves |
The 180 boards are fixed, deducible and independently counted to one answer. No hint or answer key ships in the game. The timer begins when a board opens and never pauses; only a first solve can rank. Progress and reduced-motion preference are kept in this browser. Sound follows the shared site setting.
