Sum Blocks: a number placement sum puzzle game
Sum Blocks is a sum puzzle game where you drop small number pieces onto a grid and try to make each row and column add up to the target printed beside it. Hit a target exactly and the line clears; miss it and the line turns to stone. There are eight levels, from a 5x5 board with digits 1 to 3 up to a 6x6 board with digits up to 9.
Play nowFree · No download · Runs in your browser
How to play
- Look at your piece: one, two or three blocks, each carrying a digit.
- Tap the piece to turn it, or tap NEXT to swap it with the piece waiting behind it.
- Aim at a spot on the board and tap again to place it.
- Fill a row or column so its sum equals the target to clear it and score.
- Clear the number of lines the level asks for to move on to the next one.
What it exercises
It looks like a block game, but it is really an addition puzzle: every placement is a small piece of mental arithmetic.
Mental arithmetic
Each cell belongs to a row and a column, so a single digit has to suit two running totals at once.
Planning
The smart move is often to leave the last cell of a line empty until a piece with the right number turns up.
Logic
Stones still count toward the lines that cross them, which turns a mistake into a new constraint you have to reason around.
Tips
- Watch the small chip at the end of every line: it tells you whether the line is short, exact or already too high.
- Before placing a two- or three-block piece, check both the row and the column each digit lands in, not only the line you are aiming for.
- If the current piece fits nowhere useful, swap to the next one instead of dumping it.
- Clearing two or three lines with one placement multiplies the points, and back-to-back clears build a combo worth 50% more per step.
- From level 6 stones no longer crumble on their own; the only way to break them is to clear a line that runs through them.
- On a keyboard: arrows move the piece, Enter places it, R turns it and S swaps.
Frequently asked questions
What is a sum puzzle?
It is any number puzzle where cells must add up to given totals. In Sum Blocks the totals belong to whole rows and columns, and you build them by placing pieces instead of writing digits, which makes it as much a number placement game as a calculation.
How do you play the Sum Blocks puzzle game?
Place digit pieces on empty cells. A completed line that matches its target clears and gets a new target. A completed line that misses becomes stone. Clear enough lines to finish the level.
Is this math puzzle game free to play online?
Yes. It runs in your browser on a phone, tablet or computer, is free and has no ads.
What happens when there is no room left?
If neither of your two pieces fits anywhere, you lose one of your three hearts and get a fresh board. Your level progress stays, and the run ends only when the last heart is gone.
How many levels does it have?
Eight. Levels 1 to 4 use a 5x5 board and levels 5 to 8 a 6x6 board, while the largest digit rises from 3 to 9 and each level asks for a few more cleared lines.
Is there any help for new players?
On the first level a glowing spot shows where your piece completes a line, and many early pieces are dealt so that they finish a line exactly somewhere on the board.
Ready for a round?
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