# Mathematics: checks, worked answers and next teaching moves

These are **formative samples**, not a Year 2 achievement-standard rubric. Keep a 4-column roster: `learner / exact response or model / independent or prompt + access / next move`. Choose 2–3 focus learners each day, rotate, and fill gaps in quiet stations. `Not yet observed` is a useful record. The whole class may attempt each check, but do not infer an individual strategy from a chorus answer.

## Quick answer key by day

| Day | Prompt | Expected answer and decisive evidence | If this goes wrong, teach next |
| ---: | --- | --- | --- |
| 1 | Show 205 | 2 hundreds, 0 tens, 5 ones; zero holds tens place | Put 205 beside 25; exchange bundles and read each place. |
| 2 | Match 206 | 2H, 0T, 6O, distinct from 260 and 26 | Keep all three columns; mark the empty tens with a card. |
| 3 | Larger: 309 or 390 | 390; hundreds tie, 9 tens exceed 0 tens | Compare first differing place with pieces. |
| 4 | `205, 215, __` | 225; add one ten, ones remain 5 | Build each term, say rule before filling blank. |
| 5A | Show 306 | 3H, 0T, 6O; may also be 2H,10T,6O | Rebuild 306/36; ask which place changed. |
| 5B | Order 317,371,307 | 307 < 317 < 371; pattern gap 337 | Compare tens first, then map approximate positions. |
| 6 | `7+5=12; 12−7=?` | 5; whole is 12, one part is 7 | Physically cover one part and name missing part. |
| 7 | 18 + 4 | 22; 18 + 2 + 2, or another valid strategy | Fill ten-frame from 18 to 20, then count remainder. |
| 8 | 31 − 6 | 25; check 25 + 6 = 31 | Exchange one ten for ten ones or count up 25→31. |
| 9 | Choice A/B | A: 23 cards; B: 25 seats, with correct model/unit | Act out the story and identify whether objects arrive or leave. |
| 10 | 407 vs 470; 26 − 9 | 407 has 0 tens; 470 larger; 17 cards remain | See specific follow-up below; keep place and operation evidence separate. |

## Day 5 check A — 5-minute independent sampling over rotations

**Show:** `306` with mat or words. **Explain:** what the zero is doing. **Order:** `317, 371, 307` least to greatest. **Continue:** `317, 327, __, 347`.

**Keyed examples:** A learner writes `3 hundreds, 0 tens, 6 ones` and orders `307, 317, 371`, then writes `337`: strong evidence for this small sample. A learner writes `36` for 306 but orders the other three correctly: place notation needs the next model, while comparison may be emerging. A learner writes `326` in the pattern: ask them to show the ten that is being added, then try `205, 215, __`. Record whether the correction was independent or prompted.

**Next move:** one to two short sessions with H/T/O bundles for a place error; two number-line comparisons for an ordering error; two physical `+10` sequences for a pattern error. Recheck with **different** numbers such as 405, 450, 415/451 and a `+10` run from 208. Do not repeatedly give the same key as “practice”.

## Day 10 check B — model, calculate, interpret

**Prompt 1:** Show `407`; identify the empty place; decide which is larger, `407` or `470`, with a reason. **Key:** 4H, 0T, 7O; 470 is larger because 7 tens is greater than 0 tens after equal hundreds. **Prompt 2:** “A tray has 26 cards. Nine are taken to another table. How many stay?” **Key:** 17 cards; one model is `26 − 6 − 3 = 17`, checking `17 + 9 = 26`. A learner may use counters, an open number line or part circles.

**Example decisions:**

- `407 < 470` with correct tens explanation; `26 − 9 = 17`, but no unit: ask “17 what?” and keep the otherwise correct computation.
- `407 > 470` because 7 > 0: stop at the first differing place (tens) and rebuild both. Do not drill comparison symbols alone.
- `26 + 9 = 35` for cards taken: enact taking away and redraw part/whole before repeating with 24 − 8.
- `26 − 9 = 15` with a visible count-back jump error: rehearse the jump 26→20 (6), 20→17 (3), then check with addition.

**Evidence boundary:** one correct result with a copied method is insufficient to claim independent strategy. Record reading/dictation support separately from mathematical prompting. Ask the child to show how they know using the same quantity in another representation. Share family-facing feedback as the exact skill being practised, not an ability label.

**Rights:** Original prompts/examples © NeuroForgeIO Pty Ltd 2026, SubjectNest, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Credit, link and note changes.