Slide the ○ on the y-axis to set b and tilt the ◇ on the x = 2 rail to set m — the equation y = mx + b rewrites live as you fit the line to a given equation, plotted points, or a table.
The line itself is the control: a ○ handle on the y-axis slides the whole line up and down (that is b, the y-intercept) and a ◇ handle on the x = 2 rail tilts it (that is m, rising 2m for 2 steps right, so halves like 3/2 are exact), while the equation y = mx + b rewrites with every drag. Players match a given equation, fit a line through plotted points, and fit a line to an x → y table where b and m must be inferred from the rows. It targets the m-versus-b confusion directly: every miss names which number is off and which handle moves it. Best for Grades 7–8.
A free, no-signup, no-ads math game for Grade 8 — practising slope-intercept, linear-functions, y-intercept, slope. Play in your browser on the KidsDoMath games hub or explore more Coordinates & Algebra games.
By grade level: 8th Grade Math Games
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What math does Line Builder practice? Line Builder practices Slope Intercept, Linear Functions, Y Intercept, Slope. The line itself is the control: a ○ handle on the y-axis slides the whole line up and down (that is b, the y-intercept) and a ◇ handle on the x = 2 rail tilts it (that is m, rising 2m for 2 steps right, so halves like 3/2 are exact), while the equation y = mx + b rewrites with every drag.
What grade is Line Builder for? Line Builder 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 Line Builder? Slide the ○ on the y-axis to set b and tilt the ◇ on the x = 2 rail to set m — the equation y = mx + b rewrites live as you fit the line to a given equation, plotted points, or a table.
Is Line Builder free to play? Yes. Line Builder is free, with no ads and no sign-up, and it runs in the browser on a phone, tablet or computer.