Number Grid
Expert
00:00
Classic
About expert number grids
Five-by-five grids with ten equations. The twenty-five cells inside the grid hold each of the numbers 1 to 25 exactly once, and 10–16 cells are blank — a mix of number and operation blanks. Each equation is longer too: five operands separated by four operations, so you often need to compute intermediate values to figure out what fits.
At this size, working from both ends of an equation becomes essential. If you know the starting number and the final result, the middle operations and values are heavily constrained. Expert grids take 8–15 minutes and are suited for adult puzzle solvers who enjoy KenKen or Kakuro-level challenges.
How to play Number Grid
- Every row is an equation read left to right, and every column is one read top to bottom. Its answer sits at the end of the line — down the right-hand side, along the bottom.
- The arithmetic is the ordinary kind: × and ÷ are settled before + and −. So 2 + 3 × 4 is 14, not 20.
- Division always comes out exact. A value that would leave a fraction is the wrong value.
- The numbers you write INSIDE the grid come from a fixed pool, each used exactly once — the way a sudoku uses its digits. Easy and medium use 1 to 9, hard 1 to 16, expert 1 to 25, and einstein uses −12 to −1 and 1 to 24, with no zero.
- That pool is often the only thing that settles a cell. A blank whose row answer and column answer are both blank is pinned by nothing else — the arithmetic would take any number at all.
- The answers round the edge are NOT part of the pool. They are totals: whatever the arithmetic makes them, and they may repeat.
- From hard upward some of the round operation cells are blank too, so you work out the sign as well as the number.
- Every puzzle has one solution, reachable by logic alone.