Pair up the whole domino set — free online or as a large-print book
Time: 0:00
Tap the line between two cells to join them into a domino (tap again to remove). Use every domino of the set exactly once.
How Dominosa works
A "double-n" puzzle uses the full set of dominoes — every pair {a,b} with 0 ≤ a ≤ b ≤ n. They tile a grid of height n+1 and width n+2 (double-6 = 28 dominoes on a 7×8 grid). The numbers are shown but the borders between dominoes are erased. Draw the borders so the grid splits into the complete set with each domino used exactly once. Every puzzle has exactly one logical solution.
⚂⚄
Prefer paper?
Large Print Dominosa — 110 puzzles per volume (Easy to Hard), as a paperback (also in German).