How to solve NumGrid with digit-sum strategy

NumGrid is not a guessing game. The digit-sum and parity hints make it a constraint puzzle — closer to Mastermind than to Wordle. Played correctly, most puzzles solve in 3-4 guesses. Here is the strategy.

Step 1: Read both hints before you touch the keypad

Every NumGrid puzzle shows two free hints at the top: digit sum (the sum of all five digits, range 0-45) and parity (whether the full number is odd or even). These hints exist before your first guess. Use them.

There are 100,000 possible 5-digit numbers. The digit-sum hint alone typically reduces this to between 800 and 3,500 candidates. Layer in parity and you halve again. By the time you make your first guess, you have already eliminated 97-99% of the space.

Step 2: Pick a high-information opener

A good opener tests five distinct digits, spans the keypad, and matches the digit-sum range. Some reliable defaults:

13579 — all odd digits, sum 25. Use when parity hint is “odd” and digit sum is mid-range.
02468 — all even digits, sum 20. Use when parity hint is “even” and digit sum is mid-range.
14793 — mixed parity, sum 24. Decent default when you do not have a specific reason to skew odd or even.
01234 — sum 10, covers the small-digit range. Use when digit sum is under 15.
56789 — sum 35, covers the large-digit range. Use when digit sum is over 30.

Step 3: Apply the feedback rigorously

After your opener, you have:

Up to 5 greens (digit in correct position)
Up to 5 yellows (digit in number, wrong position)
Up to 5 grays (digit not in number)

Combined with the digit-sum constraint, the candidate set typically shrinks to under 100 numbers after turn 1. A 5-distinct-digit opener with strong feedback can drop you to under 20 candidates.

Wordle’s repeat rule applies. If the answer has one 3 and you guess two 3s, only one of yours lights up; the other goes gray. That gray is information (“exactly one 3 in the answer”), not evidence of no-threes.

Step 4: The constraint-respecting second guess

Your second guess should:

Use only digits still possible (no grayed digits from turn 1).
Place the known greens in their confirmed positions.
Move yellow digits to new positions you have not tested yet.
Cover any digits you have not yet tested that are consistent with the digit sum.

If after turn 2 you still have multiple candidates, your turn 3 should be a disambiguating guess — even if it cannot itself win — that splits the remaining candidate set roughly in half.

Worked example

Hints: digit sum 19, parity odd.

Sum 19 + odd last digit + 5 digits. ~2,800 candidates. Opener: 13579 (all odd, sum 25). Feedback: 1=gray, 3=yellow, 5=green-pos-3, 7=gray, 9=yellow.

We now know: contains 3, 5, 9; does not contain 1 or 7; 5 is in position 3; the other digits sum to 19 - (3+5+9) = 2, distributed across two positions, both even (since the number is odd and 5 is in position 3, position 5 must still be 3/9 — wait, that gives digit sum 17, not 19). Let’s revisit: we have confirmed 3, 5, 9 as present (sum 17); two remaining digits must sum to 2 and be from {0, 2, 4, 6, 8} minus any already-known. Candidates: (0,2), (2,0), (0,0 — but 0 only counted once if appearing twice it’d need 2 yellows). Tight set; second guess like 23590 isolates the answer.

FAQ

How do you solve a number puzzle quickly?

Use every free constraint before your first guess. For NumGrid, the digit sum and parity collapse the 100,000-candidate space to roughly 1,000-3,000 numbers. Then make a high-information opener — five distinct digits spread across the keypad. Avoid repeated digits early; you want to maximize information per guess.

What is the best opener for NumGrid?

Use five distinct digits covering both parities and avoiding the digit-sum extremes. Strong defaults: 13579 (all odd, sum 25), 02468 (all even, sum 20), or 14793 (mixed parity, sum 24). If the day's digit sum is low (under 10), pick an opener with small digits; if high (over 35), pick large digits. The opener should give you information about both which digits are in and where they go.

How does the digit sum hint actually help?

It eliminates 97-99% of candidate numbers before you guess. There are 100,000 5-digit strings, but only ~3,500 of them sum to a specific value like 15. After parity (odd vs even) is applied, you are down to ~1,750. After your first guess returns green/yellow/gray feedback, you typically have under 50 viable candidates.

Should I guess repeated digits early?

No. Early guesses should test five distinct digits, because Wordle-style feedback gives ambiguous results on repeats (you only get one green or yellow per matching digit in the target). Save repeated-digit guesses for the second or third turn when you already know which digits are in the answer.

Apply the method now — play today’s NumGrid puzzle →

Want the full rules? How to play NumGrid.