Number Sum Puzzle Strategy & Tips
Solving a number-sum path puzzle quickly is a skill. These tips turn the target into a system you can apply to every daily grid.
Play today’s puzzleOverview
A number-sum puzzle is solved by constraint, not by trial. The target tells you the exact total your path must reach, and because every cell adds a positive amount, you can reason about which cells could possibly be involved before you draw a single line.
The single most useful habit is to bound the answer. The shortest legal path of the biggest digits and the longest legal path of the smallest digits set a window; any cell or route that cannot fit inside that window for your target can be discarded. Parity (odd/even) is another free filter: if the target is odd, your path must contain an odd number of odd-valued cells.
Strategy & tips
- Work backward from the target: list the cell values that could combine to it, then look for those values sitting next to each other.
- Use parity — an odd target needs an odd count of odd cells on the path; this alone often eliminates whole regions of the grid.
- Prune greedily: the instant your running sum exceeds the target, stop — no later cell can bring it back down.
- Count length as well as value: if only a 5-cell path can reach the target, ignore every 4-cell route entirely.
- Anchor on forced cells: a corner with the only large digit near the target is very likely on the path — start there.
Worked example
A step-by-step solve showing how to find the one path that reaches the target. (This is a small teaching grid — the daily puzzle is larger and changes every day.)
Target 19. The numbers in the highlighted cells show the connect order. Find the single adjacent path totalling 19 in this 4×4 grid.
- Step 1. Bound it: 19 is high, so the path needs a couple of big digits. The 6 (row 2) and the 5 (bottom-right) are the standouts — pulling both in gives 11 before anything else.
- Step 2. Start at the 2 on the right of row 2, step left into the 6 (running sum 8).
- Step 3. Drop down to the 2 below the 6 (running sum 10), then continue down to the 4 beneath it (running sum 14).
- Step 4. Finish by stepping right into the bottom-right 5 (running sum 19). The five cells 2, 6, 2, 4, 5 connect and total exactly 19 — the only route that does. Solved.
FAQ
- Should I always start from the biggest digit?
- Often, when the target is high — big digits are usually forced onto the path. For low targets the opposite is true, so let the target guide you.
- How does parity help?
- Adding an even number never changes the running sum’s odd/even-ness, so the count of odd-valued cells on your path must match the target’s parity. That rules out many routes instantly.
- Is there a time limit?
- No. Take as long as you like on the daily puzzle — there is no attempt cap, and your time is shown at the end just for your own record.
- Do these tips work every day?
- Yes. The puzzle structure is the same each day — only the grid and target change — so the bound-and-prune approach applies to every NumberFlow puzzle.
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