Use the learner cards after the core teaching or as a later unfamiliar recheck. They are formative: a correct number without units, domain and limitation is incomplete. Record whether the answer was independent or prompted. These invented scenarios do not certify a real pattern, service or offer.
| Card | Key evidence | If incomplete, teach this next |
|---|---|---|
| S1 library | Positive, fairly strong and roughly linear over four fictional points. The y-value is books placed, not borrowed. A defensible repair: “In these invented displays, longer tables listed more books placed; the sheet gives no borrowing data or causal test.” Book size/arrangement could affect the count. | If “borrowed” remains, point to the exact column heading before discussing causation. |
| S2 audio | Positive, strong, approximately linear in this invented set. Sizes 4, 8, 13, 16 MB rise with 1–4 minutes; increments 4, 5, 3 MB are not identical. Codec, bitrate, channel count and export settings are absent, so no universal four-minute size follows. | If “perfectly linear,” compare successive y-differences. If “all files,” ask what export settings were controlled. |
| S3 path | Positive, strong, roughly linear over simulated pairs. The 4 km/21 min pair departs from exactly 5 minutes/km (which predicts 20 min). It cannot predict a real person's route, stops or pace. | If the exact rule is accepted, substitute 4 km and compare 20 versus 21. |
| S4 seed tray | Height rises 12→15 mm, stays 15, then falls to 14 as hours rise 2→8. No single positive linear claim or “always increases” fits even the authored points. No actual plants, methods or environment were measured. | If “negative association” is claimed for the whole set, read pairs in x order and identify rise/plateau/fall. |
| M1 posters | A(n)=25+4n; B(n)=55+2n. Equality 2n=30 → 15 posters, $85. At 10: A $65, B $75; at 20: A $105, B $95. Paper quality unverified. |
If setup is multiplied by n, identify the one-off charge. If price is called quality, name missing specifications. |
| M2 music | A(h)=40+18h; B(h)=70+12h. Equality 6h=30 → 5 hours, $130. At 6: A $148, B $142; B lower by $6. Actual room access, equipment, cancellation/terms unverified. |
If an intersection is a dollar amount only, ask for its ordered pair and substitution into both models. |
| M3 transport | Equality 100+8d=40+14d → 60=6d → 10 km, $180. At 5: A $140, B $110; B lower by $30. At 15: A $220, B $250; A lower by $30. Actual load, distance measure and fees absent. |
If plan ordering never changes, test d=5 and d=15 on both sides of the intersection. |
| M4 containers | Equality 15+5w=27+3w → 2w=12 → 6 weeks, $45. At 8: A $55, B $51; B lower by $4. Cleaning, delivery and suitability absent. |
If equal price is confused with equal value, ask which service attributes the rule does not contain. |
Scoring for feedback: Look for (1) correct source variables, (2) valid mathematical operation, (3) units and domain, and (4) a conclusion bounded to the invented data. If an access route changes the output mode, judge the same four pieces of reasoning and note the support used. A learner may challenge a source claim with a well-supported alternative interpretation. Choose one new card for a later independent recheck rather than repeating an item already modelled.
Reuse: Original SubjectNest keys © NeuroForgeIO Pty Ltd 2026, CC BY 4.0. Credit source/licence and mark changes.