What’s inside:
- Part 1 · Meet the Explorer — an animated hiker on an SVG number line. Students pick a start, an operation, and a number, then watch the move; subtraction visibly rewrites itself as “add the opposite” in the caption before the walk.
- Part 2 · Predict the Landing Spot — random add/subtract problems; students commit with a big touch-friendly slider (gold marker on the line) before the explorer moves, with a running prediction score.
- Part 3 · The Expedition Calculator — accepts negatives and decimals for all four operations, and outputs numbered steps with the why: same-sign vs. different-sign addition, “add the opposite,” and the sign-decided-first rule for × and ÷. Divide-by-zero handled kindly.
- Part 4 · Quiz — 10 questions, both orders shuffled, every distractor named to a trap, Big Idea lines, correct-answer reveal, gold progress bar, and 4 result tiers that route students back to the exact Part that reteaches what they missed (tracked by question tags).
Misconception coverage summary: Questions 1, 3, 5, 9, and 10 target the addition traps — applying “two negatives make a positive” to sums, adding absolute values when signs differ, taking the wrong sign, and moving the wrong direction in temperature/elevation contexts. Questions 2 and 8 target subtraction errors — dropping the negative in 5 − (−2) and flipping the wrong number when rewriting as “add the opposite” — while Question 4 targets the beliefs that distance can be negative or is found by subtracting digits in any order. Questions 6 and 7 target multiplication/division sign-rule errors: negative × negative = negative, dropping the quotient’s sign, and confusing ×/÷ with adding or subtracting.
