randRange(2, 20) randRange(1, A - 1)
init({ range: [[0, 12], [-1, 1]] }); var equation = rand(2) === 0 ? "\\Huge{\\blue{" + A + "} - \\red{" + B + "} = {?}}" : "\\Huge{{?} = \\blue{" + A + "} - \\red{" + B + "}}" label([0, 0], equation, "right");
A - B
drawCircles(A, BLUE);
crossOutCircles(A, B, RED);

We began with \blue{A} dot and crossed out \red{B} of them. We began with \blue{A} dots and crossed out \red{B} of them.

We are left with A - B dot.

We are left with A - B dots.