Equation Climb

How to play

Bounce up a coordinate grid, platform by platform, and grab the star at the point you’re asked for. At base camp, answer three questions; each right answer is a spring for a super jump.

On a computer

Left and right arrow keys to move (you bounce on your own), Space for a spring jump

On a phone

Hold ◀ ▶ to move; tap Spring for a super jump

What you’ll revise

Class 9 Maths: Coordinate Geometry, Linear Equations in Two Variables

1. Climb 1 · Coordinate geometry

   • A point is written (x, y): x is the abscissa and y is the ordinate.
   • The x-axis and y-axis meet at the origin, (0, 0), and divide the plane into four quadrants.
   • Signs in each quadrant: I (+, +), II (−, +), III (−, −), IV (+, −).

2. Climb 2 · Linear equations

   • A linear equation in two variables has the form ax + by + c = 0, where a and b are not both zero.
   • x + 2y = 5 can be written x + 2y − 5 = 0, so a = 1, b = 2 and c = −5.
   • Word problems become equations: “a pen costs twice as much as a pencil” is x = 2y.

3. Climb 3 · Solutions

   • A solution is a pair (x, y) that makes the equation true.
   • Check by substituting: (1, 2) solves 2x + y = 4, because 2 × 1 + 2 = 4.
   • A linear equation in two variables has infinitely many solutions.