What’s inside:
- Part 1 · Keep the Scale Level — an SVG two-pan balance with green x-boxes and gold unit coins. Students solve preset equations with staged legal moves: “Take q coins from BOTH sides” → “Split BOTH sides into p equal groups,” with the equation line updating (2x + 3 = 7 → 2x = 4 → x = 2). The ⚠️ cheat button removes coins from one side only — the beam visibly tips and the caption explains why the = promise broke.
- Part 2 · Graph It Right — random inequality graphing with commit-before-reveal. 40% of problems present a negative-coefficient form like −2x < 6 that requires the flip before graphing. Students toggle Open ○ / Closed ● and Shade Left / Right, Lock It In, then the correct ray is drawn and the feedback names exactly which choice went wrong (circle vs. direction vs. missed flip), with a running streak.
- Part 3 · The Two-Step Solver — any px + q compared to r with =, <, >, ≤, or ≥. Steps narrate the reverse order of operations (undo the adding first), a cream-highlighted 🚨 FLIP ALERT fires whenever dividing an inequality by a negative, a substitution CHECK verifies the answer, an ESTIMATION sanity step models rounding-as-error-alarm, and inequality solutions get graphed on a live number line.
- Part 4 · Quiz — 10 questions spanning solving, the flip, graph reading, translation, and estimation, with four tiers routing back by tag.
Misconception coverage summary: Questions 1, 2, and 4 target solving-order errors — adding instead of subtracting the constant, skipping it entirely, dividing only some terms (the x = −1 trap), stopping at 3x = 15, and multiplying instead of dividing. Questions 5–8 target inequality traps: the missed flip when dividing by a negative, symbol-strength drift (< becoming ≥), open/closed circle confusion, arrow-direction errors, and the exact-boundary case where 14 > 14 fails a strict inequality. Questions 3, 9, and 10 target translation reversals (“seven less than twice” → 7 − 2n), swapped rate-and-start setups, ignored or mis-signed constants, and estimation failures like answering the wrong question or subtracting one item’s cost instead of three.
