Drag a ⊕ probe to the one lattice point that satisfies both equations of a system — LOCK IN plugs its x and y into each equation on screen, and parallel or disguised same-line systems must be called as no solution or every point.
Two linear equations are graphed and the only control is a ⊕ probe: drag it to the point where both lines meet and LOCK IN substitutes its x and y into each equation right on screen, so the verdict is the arithmetic (3 = 2(2) − 1 ✓). Later rounds hide line 2 so the probe slides along line 1 while the live substitution of line 2 is read off until it agrees, and a cases mode mixes one crossing, parallel lines (∅ no solution) and a same line disguised as 2y = 4x − 2 (every point works). It targets the belief that every system has exactly one answer and that the picture alone is proof. Best for Grades 7–8.
A free, no-signup, no-ads math game for Grade 8 — practising systems-of-equations, linear-equations, substitution, parallel-lines. Play in your browser on the KidsDoMath games hub or explore more Coordinates & Algebra games.
By grade level: 8th Grade Math Games
More like this: Inequality EngineElimination EngineExpression Exchange
What math does Crossing Lines practice? Crossing Lines practices Systems of Equations, Linear Equations, Substitution, Parallel Lines. Two linear equations are graphed and the only control is a ⊕ probe: drag it to the point where both lines meet and LOCK IN substitutes its x and y into each equation right on screen, so the verdict is the arithmetic (3 = 2(2) − 1 ✓).
What grade is Crossing Lines for? Crossing Lines is built for Grade 8 (ages 13–14). It sits in the Coordinates & Algebra strand, and it ramps across 8 levels so younger or older players find their own pace.
How do you play Crossing Lines? Drag a ⊕ probe to the one lattice point that satisfies both equations of a system — LOCK IN plugs its x and y into each equation on screen, and parallel or disguised same-line systems must be called as no solution or every point.
Is Crossing Lines free to play? Yes. Crossing Lines is free, with no ads and no sign-up, and it runs in the browser on a phone, tablet or computer.