Back to the arcade
45-second rounds · 3 min read
Play Sum GridWhat is Sum Grid?
Find a subset of number tiles whose total equals the target. You are choosing a combination, not entering a calculation in a text field. Several combinations may legitimately solve the same board, and you do not have to discover the combination used when the puzzle was generated. An exact total is what matters.
Rules and controls
- Tap a tile to select it, and tap it again to remove it. The running total updates as you work. Select at least two tiles and press Check sum when the total matches the target. A successful check completes one objective and replaces the board. An incorrect check records a mistake while keeping your selections available for correction. Clear selection empties the working set.
- Controls respond only during active play. The countdown and the brief change between boards are pauses, not opportunities to submit the next answer early. Touch controls and native Tab/Enter button activation follow the same replay rules.
Use the controls displayed above the playfield. Touch buttons and keyboard shortcuts are shown before the round begins.
Scoring and rewards
The game scoreboard gives 100 for each correct exact sums objective and subtracts 25 for a recorded mistake, with a minimum displayed score of zero. Only new, accepted objectives count; waiting or repeating completed work does not create achievements.
Reward points use verified performance against this game’s reference pace rather than its raw scoreboard. The reference is: Plan a subset of at least two tiles before checking its sum. Full reference performance corresponds to 40 base reward points and 60 XP per minute; the account’s level bonus is applied separately.
Points and XP scale with objective performance, precision, and round length. At full reward performance, a 45-second round earns up to 30 base points and 45 XP. Each level gained adds a 0.1% point bonus. Guest practice has no reward balance.
For eligible rewarded rounds, points remain pending until the sponsored claim’s 12 seconds of focused time and fresh hCaptcha are complete. No ad click or purchase is required.
How difficulty changes
Higher difficulty increases available number values and may build the target from a larger subset. Every board is generated from a real combination, so a valid solution exists. Duplicate number values are separate tiles and may each be used once, but the same physical tile cannot contribute twice.
Difficulty increases after every three starts of this game during a UTC day, up to level 10, and resets at 00:00 UTC. Your player level and its point bonus are separate from the game’s daily difficulty.
Strategy
Plan the next move
Subtract your running total from the target to identify what remains. Looking for an exact remainder is often faster than adding every possible group from scratch.
Check before committing
Try small combinations first, then expand deliberately. If two tiles nearly reach the target, inspect whether replacing one tile solves the difference before adding several more selections.
A worked example
- The target is 14 and the grid includes tiles showing 6, 5, and 3.
- Select those three tiles; the running total becomes 14.
- Press Check sum to commit the answer. Merely reaching the total without checking does not finish the board.
Common mistakes
- An exact target reached with only one tile is not accepted; the challenge requires a combination.
- Selections toggle. Clicking a highlighted tile again removes its value rather than adding a second copy.
Questions
Is there only one solution?
No. Any selected subset with at least two tiles and the exact total is accepted.
Do selection changes count as mistakes?
No. Only an incorrect check counts as a mistake; exploring or clearing a combination is allowed.
