Cross Math: What It Is, How to Play, and Winning Strategies
What is a math crossword?
A math crossword (also called an arithmetic crossword or number crossword) looks like a classic crossword grid, but you fill the white cells with digits instead of letters. Each horizontal and vertical entry forms a math expression using the symbols in the grid (+, −, ×, ÷, =) and must evaluate to the number shown at the row or column end.
Always check the rules on the puzzle: many versions calculate left-to-right (ignoring PEMDAS), while others use standard order of operations. Divisions usually yield whole numbers, and each cell holds one digit (0–9).
How to solve a math crossword (step by step)
Scan for givens & easy lines
Start with rows/columns that already show digits or have an equals sign with a small target (e.g., 1, 3) or a large product (e.g., 72). These often force specific factor pairs.Work both directions
Every placed digit affects a crossing expression. After each placement, re-check intersecting rows/columns for new deductions.Prefer ÷ and × first
Products and quotients have fewer possibilities than sums. List the factor pairs or divisors that match the target.Use digit logic
Parity: odd ± odd = even; odd × even = even.
End-digit rules: any number ending in 0 or 5 is divisible by 5; even numbers are divisible by 2.
Sum checks: when a row must total 14 with two adds, the addends must fit 14 and respect the crossings.
Record pencil marks
Jot tiny candidates in each cell (e.g., {2,4}). Eliminate as you learn more—this avoids blind guessing.Only guess last
If stuck, pick the cell with the fewest candidates, branch once, and backtrack if it breaks a rule.
Tips & tricks that save time
Lock integers: If the puzzle requires whole-number division, immediately discard any quotient that’s not an integer.
Exploit ones & zeros: To hit =1 via division, the numerator and denominator must match; to hit =0 via subtraction, terms must be equal.
Anchor numbers: Given digits (like a fixed 2 or 9) often determine nearby operations.
Check totals early: Column totals at the bottom are powerful; use them to validate partial rows.
Symmetry sweep: Grids with mirrored blocks often mirror difficulty—finish a “simple” side, then mirror the logic.
