Confirm-and-skip candidate: Fractions 17 and 19–21 substantially overlap this anchor. A secure baseline plus delayed check should replace re-teaching with the Build Scale Lab or a gated stretch task.
Success criteria
- I can prove equivalent forms, not only recall them.
- I can choose fraction, decimal, or percent to communicate clearly.
- I can use a fraction as a scale factor in a new build context.
Explain
Show 3/4, 0.75, and 75% on one hundred-grid or number line. Explain what stays the same when the notation changes and why percent is especially useful for comparing “out of 100.”
Independent practice
Write 3/8 as a decimal.
Write 3/4 as a percentage. Enter the number only.
Which form is usually quickest for comparing 17 correct answers out of 20 with 43 out of 50?
A common out-of-100 scale makes the comparison visible.
Transfer — Build Scale Lab (offline)
Build a paper/cardboard arcade, model room, or materials plan at 3/4 scale. An original 8 × 5 unit panel becomes 6 × 3.75 units. Label the model, calculation, and why both dimensions use the same scale. This is a physical plan, not a coded game or another recipe task.
Delayed check
One week later, prove that 7/20, 0.35, and 35% are equivalent, then use the most useful form to compare it with 1/3.
Evidence and next step
Save the scale plan, model photo, and explanation at jeremy/portfolio/math/unit-3/build-scale-lab/README.md.
- Secure baseline + independent delayed proof + transfer → mark confirmed and skipped/secure and apply the stretch gate.
- Conversion secure but representation choice weak → compare three real labels or scores.
- Equivalence error → return to a hundred-grid or common denominator, then retry.