How to Play Sumplete: Beginner's Guide for Adults
Sumplete is a number puzzle where you delete numbers from a grid so the ones left in each row and column add up to the target sums shown on the edges. There's no filling in — just elimination, and no guessing. Start with any row or column whose target is zero and cross out every number in it. Then delete any single number that is larger than its row or column target.
What Is Sumplete? (Sudoku's Mirror Image — You Delete, Not Fill)
If you've spent years with Sudoku, the first thing Sumplete does is flip your instinct backward.
In Sudoku, you start with a mostly empty grid and fill numbers in. In Sumplete, you start with a full grid and take numbers away. Delete the ones that don't belong, leaving only the cells that make each row and column hit its target sum. Along the right side, each row shows a target sum; along the bottom, each column shows one too.
Clicking through cell states: one click → red cross (eliminated); two clicks → green circle (confirmed); three clicks → blank (undecided).
The AI-origin story: Sumplete appeared in 2023, created by Daniel Tait. According to Tait's own account on sumplete.com, the puzzle was "invented and coded by AI (ChatGPT)" — he prompted ChatGPT through multiple iterations, and the AI "not only came up with the idea, but also coded the game, designed it and even named it."
The arithmetic is basic: single-digit additions and small totals. If you can add numbers up to about 30, you have all the math you need.
New to this family of puzzles? Brain games like Sudoku gives a quick overview of Sumplete alongside six other logic puzzles.
Start With the Zeros (The Easiest First Move)
Every Sumplete grid has one gift hidden in plain sight: any row or column whose target sum is zero.
If a row's target is zero, no number in that row can remain — the only way to hit zero with positive numbers is to delete all of them. Cross out every number in that line immediately. The same logic applies to columns.
- Any row or column with a target sum of zero → cross out every number in it.
- No math required. It's the fastest free move on the board.
Every cell you cross out in a zero line belongs to a crossing row or column too. Once eliminated, it reduces the available numbers in that crossing line — and may unlock your next move there.
Cross Out Anything Too Big (Overage Elimination)
The second fastest move: if any single number is larger than its line's target sum, delete it immediately.
If one number already exceeds the target on its own, keeping it pushes the sum over regardless of what else you do. As sumplete.com's guide puts it: "cross out any number that would result in the total of that row or column to exceed the target number."
Worked example (directly verified):
Row target is 6. The row contains 6 and 8.
- Can 8 stay? 8 > 6, so no. Delete it.
- What remains: just the 6. Sum = 6 = target. ✓
A slightly trickier case:
Row target is 9. The row contains 4, 11, and 5.
- Can 11 stay? 11 > 9, so no. Delete it.
- Remaining: 4 and 5. Sum = 4 + 5 = 9 = target. ✓
Run this check on every row and column before deeper logic — it frequently eliminates one or two cells per line with almost no effort.
What about a number that exactly equals the target? If it's the only remaining candidate, circle it. If it's one of several, check the other cells too.
Think in Sum Combinations (Don't Just Guess)
Once you've cleared zeros and overages, you're into the part that takes real thought — and delivers the most satisfaction.
Each remaining line has a target reachable in several ways. A target of 10 can be 1+9, 2+8, 3+7, 4+6, or 5+5. As sumplete.com notes, "there are multiple ways to achieve a sum clue target number" — the skill is narrowing those options with constraints you already know.
The key constraint: cross-referencing rows and columns.
Every cell belongs to two lines at once. Whatever decision you make has to satisfy both its row target and its column target simultaneously.
Worked example (directly verified):
Row A has two remaining candidates: 3 and 4. Row A's target is 7 — both must stay: 3 + 4 = 7 ✓.
Now check the column containing the 4. Target: 6. Other candidate: 2. If 4 stays (Row A requires it): 4 + 2 = 6 ✓. Both constraints satisfied.
This is the cross-reference move: confirm a cell in one direction, then check whether it holds in the crossing direction. When it doesn't, delete it.
Why "don't guess" is the rule: a wrong decision corrupts two lines at once, and errors compound fast. Work by elimination, as sumplete.com describes: "working by elimination, not by guessing." Let the crossing lines tell you which numbers survive instead of committing to a combination at first glance.
Want to try the same kind of thinking in a faster format? That's exactly what Make 10 is about.
Sumplete and Make 10 share the same core skill: recognizing which numbers reach a given target. Make 10 is a quick way to get comfortable with that number-combination thinking before tackling a harder Sumplete grid.
How to Get Unstuck (and the Auto-Mark Shortcut)
Every solver hits a wall. Here's the order to try:
1. Re-run the zero and overage checks. As cells disappear, lines that had no obvious moves may now qualify. New eliminations feed back and create new moves.
2. Go after the most constrained lines. Low or high targets relative to the numbers present have fewer valid combinations — start there. The tighter the constraint, the more logic forces your hand.
3. Check your crossing lines. Progress on rows changes what's available in columns. Re-examine every column those rows touch.
4. Take a break. Sumplete is a daily puzzle — no clock. Stepping away often surfaces a move you missed.
- Zeros — cross out every number in any zero-target line
- Overages — delete any number larger than its line's target
- Combinations — identify which sum combos fit each remaining line
- Cross-reference — check every cell against both its row and column
- Repeat — feed new deductions back through all four steps
The auto-mark shortcut: once you know which cells to keep, click the sum clue itself. As Sumplete's glossary describes it, this means "directly clicking a sum clue value on the perimeter of the playing board to automatically eliminate remaining unchecked cells" — especially useful on larger grids.
Is Sumplete Good for Your Brain? (Honest Answer)
Sumplete gives you a focused workout in addition, systematic elimination, and pattern recognition. It's genuinely engaging — the "just one more" feeling is real.
On broader cognitive claims: playing logic puzzles keeps you practiced at logic puzzles, which is useful. Whether that translates to general memory or reasoning gains is more limited and task-specific than puzzle marketing often suggests. For a fuller look, brain games for seniors covers the evidence directly.
Sumplete's closest relatives are Kakuro and Killer Sudoku — both use combination thinking, but ask you to fill empty cells rather than delete from a full grid. Same mental skill, opposite direction. If you've worked through how to solve Kakuro or how to play Killer Sudoku, those instincts carry directly into Sumplete — just flip from "what goes in" to "what comes out."
Just for fun — not medical advice.
Frequently Asked Questions
Is Sumplete hard for beginners?
The 5×5 grid is the right starting point — under five minutes and teaches all the core moves. Difficulty rises with grid size, but the same four steps (zeros, overages, combinations, cross-reference) apply at every level. Most beginners find the logic clicks after two or three completed grids.
Do I need to be good at math to play Sumplete?
No. The arithmetic is basic addition — single-digit numbers, small sums. The real skill is logical elimination: which cells can and cannot stay. If adding numbers like 3 + 4 + 7 is comfortable, you have all the math Sumplete needs.
Did an AI really create Sumplete?
Yes, according to its creator. Daniel Tait describes the process on sumplete.com: he prompted ChatGPT to design a new puzzle like Sudoku, and the AI "not only came up with the idea, but also coded the game, designed it and even named it." Tait released it in 2023.
Is Sumplete like Sudoku?
They share the grid structure and the requirement to satisfy every row and column — but the mechanic is opposite. Sudoku starts empty, you fill it. Sumplete starts full, you delete. Sudoku uses placement rules (each digit once per row, column, and box); Sumplete uses sum targets with no restriction on repeated numbers.
Where should I start on a Sumplete grid?
Zero-target rows and columns first — cross out everything in them immediately. Then scan for any number larger than its line's target. Together, these two moves often clear a good chunk of the grid before you need to think hard.
Ready for a quick number puzzle right now? Make 10 is open in your browser — place blocks so rows or columns sum to ten, and they clear. Same number-combination instinct as Sumplete, different format. No account, no download.
More from the Make10s blog: brain games like Sudoku · how to solve Kakuro · how to play Killer Sudoku · brain games for seniors · all posts
Sources: Sumplete — About (Daniel Tait) · Sumplete — How to Play · Sumplete — Glossary