Teacher answer boundaries… | Year 8 Inquiry · T1 W3–4 · Teacher key

This key and the fresh checks are publicly accessible in the library. Give learners a clean prompt on the right day; use a locally changed case if prior access matters. Record independent / prompted / not yet observed at the criterion level, plus exact learner words, first attempt and access route. The 0/1/2 descriptions below guide one next teaching move; they are not a pass/fail total or whole-year standard. A calculator supports arithmetic; it cannot supply a source citation or make a universal claim defensible. Paper-only, AAC, speech and digital interaction produce different evidence. No student work belongs in a public pack.

Daily next moves

Day	Evidence to recognise	If missing, teach next
11	`2(24+18n)=48+36n`; at `n=4`, each drawn rail is 96 cm and both sum to 192 cm. No real wall or reader count follows.	Lay out two identical RAIL strips; distribute the 2 to margins and panels, then label per rail/combined separately.
12	Two inspectable paper criteria, a reasoned flat/folded material choice and a limit of paper testing.	Sort requirements into DRAWING, PAPER TEST and REAL SITE UNKNOWN; rewrite “good for everyone” as a specific question.
13	An investigable fold-shape question; same paper/span/tab/placement/stop rule; own observations or clearly labelled constructed numbers. A descending tab gains kinetic energy as gravitational potential decreases.	Rehearse the protocol with CHANGE/KEEP/STOP cards. Model energy with a light paper tab only, without numerical energy claims.
14	Two original visual layouts show a deliberate spacing/emphasis change; reader's exact response is distinct from predicted audience effect. Constructed means `4/3` and `13/3` are not real capacity claims.	Compare the same words in two placements, then ask a reader to locate SOURCE and LIMIT before interpreting mood.
15	See fresh Check A key below; do not reuse the teaching rail values.	Choose A1–A4 next move; re-sample on a different source later.
16	`5+15d≤50` gives integer `0≤d≤3`; three uses 50 and four needs 65 minutes. Demonstrations are not people, and question time is not included.	Put DEMONSTRATIONS and PEOPLE on separate cards; substitute d3/d4 before rewriting the headline.
17	F/G at p4 are 20/16, at p8 28/32, equality at p6 gives 24/24. At p4, invented G price 6 makes G24, above F20. Budget/quality kept distinct.	Put setup and per-panel fee on separate strips; write p as TOTAL panels and check units before any recommendation.
18	Actual tool route tests 0, valid whole and invalid entry; interface change is tested against the user story. Paper route is labelled design reasoning.	Trace INPUT → RESULT + UNIT → LIMIT → ERROR with a paper card; ask what a reader could miss and revise one label.
19	Recommendation cites B/C/E/F separately, names a model result and physical/reader limitation, compares quoted cost at a stated count and revises an original visual caption. Actual delivery mode is recorded.	Use four cards SOURCE, RESULT, LIMIT, REQUEST; have a private reader locate each in the draft.
20	See fresh Check B key below; `r` demonstrations and `c` kits are not people.	Choose B1–B4 next move and use a fresh count/source for later transfer.

Check A Day 15 worked key

3(8+5k)=24+15k: the 3 multiplies both the 8 cm title space and 5k cm label length. At k5, one ribbon is 33 cm and three combined are 99 cm; the latter is not a 99 cm single ribbon or a measured real board. At k6, one is 38 cm, exceeding the 33 cm drawing. The supplied result says nothing about adhesive, site width or readers finding labels. “Every real noticeboard”, “every reader” and “proves it” exceed the source. A specific next step may test an additional adhesive allowance in a new paper model, measure an authorised actual site with local safety process, or run a consented reading test on a paper mock-up. It must state what is measured/observed and cannot claim that one test establishes all sites or readers.

Worked caption: “Each of three drawn paper ribbons has 8 cm for a title and five 5 cm labels, so each uses 33 cm and all three use 99 cm together in this model. This matches the 33 cm drawn line for each ribbon. It does not prove that any real noticeboard can hold them or that every reader can locate each label. A paper mock-up could be reader-tested for label order, and any real board would need authorised site measurements and mounting checks.” Equivalent source-bound wording earns evidence.

Criterion	0 · absent/incorrect	1 · developing	2 · secure in this sample	Immediate next move for 0/1
A1 · equivalent rule	Multiplies only one part or swaps one/three ribbon units.	Gives `24+15k` without explaining 3 groups or units.	Explains 3 × 8 and 3 × 5k as total paper length, and identifies one-ribbon rule separately.	Use three equal strips and read title/labels on each before combining.
A2 · substitution and scope	Wrong source count or says 99 cm is one real board.	Gives 33 or 99 without clear per-ribbon/combined distinction.	Shows k5 gives 33 cm per drawn ribbon, 99 cm combined; may also use k6 as contrast.	Label PER RIBBON and ALL THREE before computing; use a calculator separately if needed.
A3 · headline reach	Accepts universal site/reader claim.	Spots an overclaim but only says “could be wrong”.	Cites absent adhesive, real board or reader observation to explain why a named claim outruns the paper note.	Put QUOTED CLAIM beside SOURCE MEASURED; ask what is missing between them.
A4 · correction and next test	No bounded caption or observable next step.	Includes a limit but vague “test it”; source or audience unclear.	Reader-facing correction uses sourced result, explicit limit and one checkable paper/authorised real test.	Order result → condition → unknown → what exactly to observe next.

Feedback decision: A1/A2 weak → representation and unit labels; A3 weak with sound maths → source reach; A4 weak → make a specific test question. Keep calculation and interpretation feedback separate. Do not convert 8 criterion points into an achievement-standard claim.

Check B Day 20 worked key

6+8r≤38 gives 8r≤32, so r≤4 for non-negative whole demonstrations. Four use 6+8×4=38 minutes; five need 46, beyond the model slot. For four kits, H 10+3×4=22 tokens and J 5×4=20; both are within the fictional 25-token budget, and J is 2 lower on listed cost. The source gives no kit yield per demonstration, people count, questions, changeover, material quality or reader access; even if four demonstrations and four kits were prepared, “everyone finishes” is not established. A specific next question might ask how many people are expected, how many usable kits each demonstration needs, who can access the instructions or how long questions take. The source is a model, not a real workshop approval.

Worked editor note: “The 38-minute paper model fits four complete demonstrations after six minutes of setup; a fifth would need 46 minutes. At four kits, Supplier J's listed 20 tokens are two less than H's 22, and both fit the invented budget. Those figures do not show that everyone will finish a zine, because the number of readers, kit use and question time are unknown. Before changing the poster, the fictional editor should ask how many usable kits a demonstration needs for the intended group.” Equivalent precise questions are valid.

Criterion	0 · absent/incorrect	1 · developing	2 · secure in this sample	Immediate next move for 0/1
B1 · time condition	Treats 4 as people or accepts five in 38 minutes.	States four but not setup/8-minute/rule condition.	Tests or solves `6+8r≤38` and contrasts r4=38 with r5=46 minutes for complete demonstrations.	Draw SETUP plus repeated RUN boxes; substitute r4/r5 with units.
B2 · cost and budget	Confuses c kits with r runs or computes a wrong quote.	Gives J20 without H22/budget context.	At c4 gives H22/J20, both within budget25, J lower by 2 on quoted cost only.	Keep r/c on different cards; build setup + per-kit strip.
B3 · unsupported poster	Says all visitors finish because four runs/kits exist.	Spots overclaim without naming missing evidence.	Explains that person count, kit use, questions or access is unmeasured, so the universal finish claim cannot follow.	Ask “Four of what, and how many people?” before revising the headline.
B4 · recommendation	No linked decision or checkable next question.	Some correct data, but no clear limit or specific question.	Ordered reader note retains time and cost results, qualifies the promise and asks a measurable next question.	Order time → cost → unknown → question, then have a reader paraphrase.

Feedback decision: B1/B2 weak → model variables and units; B3 weak despite sound calculation → English source reach; B4 weak → audience-facing paragraph and specific question. One check cannot determine a subject achievement standard or suitability of any real event.

Optional quick boundaries

Day	Expected answer boundary
11	`2(6+3x)=12+6x`; T(2)=120 cm for two rails combined, with R(2)=60 cm each.
12	Criteria name a paper feature and observable check; paper reuse benefit is hypothetical until measured.
13	Flat constructed mean `4/3≈1.33`; falling paper tab transfers gravitational potential toward kinetic energy without quantified energy.
14	Different spacing may affect one reader; crease differences are a plausible error source, not a measured effect in the fallback.
15	Extras return to earlier sources only, after collecting the new check.
16	`4+9g≤40`: g4 uses 40, g5 needs 49, so at most four whole games in the model.
17	p6 F/G each 24; F-only added two-token hypothetical makes F22 at p4 versus G16, still G lower.
18	A negative or fractional entry needs a plain-text whole-number error; no real site promise follows.
19	An exact source, unit and limit must accompany a recommended caption; no public message is sent.
20	Extras revisit older sources only after the held-out response is collected.