Hard math crossword
A hard math crossword is the difficult one: all four operations, a few longer equations, and at least one round where no cell solves itself.
Hard is the difficult math crossword. It uses addition, subtraction, multiplication and division. Numbers stay in 1 to 60, tighter than Medium, because division has to come out exact. The grid is up to 11 by 11, with 11 or 12 equations, and about 55 percent of the number cells are blank.
Most lines are still A operator B = C. One or two are longer: A operator B operator C = D. Multiplication and division come before addition and subtraction. 12 ÷ 3 + 5 is 4 + 5, which is 9. 3 + 4 × 2 is 3 + 8, which is 11. 12 ÷ 5 never appears, because division here is always exact, and a step that is negative or not a whole number is rejected.
Expect a chain of at least five rounds, and at least one round where no equation has a single blank. A candidate has to satisfy every equation that uses that cell, including a seven-cell line and the equation that crosses it.
The scoring target is ten seconds per blank, about two minutes and ten seconds. This is the set for adults who want more than a warm-up. Expert keeps the same operations and pushes the numbers, the blanks, and the length of the chain.