Sumrex hints — 2026-05-04

Three hints for today's Sumrex (#15), escalating from gentle to almost-the-answer. The six-rex solution sits behind a toggle at the foot of the page.

Hint 1 — how big can a single digit get?

Reveal hint
Target sum
18
Six rexes — one per row, one per column, one per region — must add up to exactly 18.

Your six rexes must sum to exactly 18. Even if every other row plays its smallest available digit, any single rex can be at most 7. So any cell with a digit greater than 7 can be crossed out straight away.

Hint 2 — your first rex

Reveal hint
7
3
8
8
5
8
5
8
9
5
4
5
7
2
1
3
4
1
1
7
9
6
1
1
2
4
7
7
4
7
4
5
8
6
9
7

Scan the columns once the early crossings are down. Column 3 ends up with only one candidate row — row 3. That cell must be a rex.

Hint 3 — closing the budget

Reveal hint
7
3
8
8
5
8
5
8
9
5
4
5
7
2
1
3
4
1
1
7
9
6
1
1
2
4
7
7
4
7
4
5
8
6
9
7

By this stage you should have 4 rexes down, with their digits totalling 12. That leaves a budget of 6 across your final 2 rows. Only one arrangement of your remaining candidates sums to exactly 6 — those must be your last rexes.

Show today's answer
7
3
8
8
5
8
5
8
9
5
4
5
7
2
1
3
4
1
1
7
9
6
1
1
2
4
7
7
4
7
4
5
8
6
9
7

(R1C2=3) (R2C6=5) (R3C3=1) (R4C5=1) (R5C1=2) (R6C4=6) — the six digits sum to 18.

Play this Sumrex puzzle →

More: how to play Sumrex past Sumrex puzzles

FAQ

How do I play Sumrex on mobile?

Sumrex works on any modern mobile browser. Tap a cell to cycle it through empty, crossed-out, and rex — no typing required.

What time does Sumrex reset?

00:00 UTC, every day. Whatever timezone you're in, the same Sumrex is live worldwide on a given date.

Is Sumrex always solvable by pure logic?

Yes. Every Sumrex board is generated, then re-solved by a sum-and-uniqueness checker that only uses forced moves. If a candidate board needs a guess to crack, it's rejected before it reaches the queue.

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