# Day 20 — Use a number tool that helps

**25 minutes · AC9MFN01 and AC9MFN03 (0–20 application, partial); brief AC9MFN02 retrieval · educator review pending**

**Success today:** The child chooses a way to build, name or order a number to 20 and compare two collections, then explains or demonstrates why the answer fits. A child can work in a smaller range while the next instruction targets 20.

**Prepare per pair:** two mats, four ten-frames, 40 counters, numeral cards 0–20, path and selected [scene cards](print-aids.md). Keep the [formative check](assessment.md) nearby, but do not attempt its full set of items in one 25-minute class block.

1. **Reconnect, 3 min.** Briefly show four dots for optional 1–5 subitising retrieval; ask what group the child saw. Then point to 19 on a number path and ask what comes next. Responses need not be fast.
2. **Model, 5 min.** Choose the pretend community-garden card: 19 plant labels and 20 pot labels. Build each set on two ten-frames, count both, and say, “Nineteen has one fewer than twenty. I checked the counts and can see one empty space in its second frame.” State the task, not a story about an actual family.
3. **Play: choose a useful scene, 10 min.** Partners choose two different [scene cards](print-aids.md), one make-a-set and one comparison. Choices include a library, bus stop, gallery, bike repair, theatre, observatory and more. One child builds or directs; the other checks with a new strategy, then swap. Ask, “What did the frame, path or count help you notice?” A quiet individual route uses the same two cards.
4. **Independent try, 4 min.** Give fresh cards `14` and `18` and an uncounted supply of objects. “Build both, choose their numeral labels, and show which has more.” For a child still consolidating 0–10, use `4` and `8` and record that range explicitly. Do not prompt the answer before observing.
5. **Check and close, 3 min.** Ask, “If you were unsure, what could you use to check?” **Key:** `18` names the larger of the independent sets; 18 has four more than 14. Counting, pairing or path order can justify the relation. The four-dot retrieval total is four; 20 follows 19.

**If the child copies a partner's answer:** Give a different private set before marking independent evidence. If frame work is correct but a loose set is not, repeat the same quantity in a loose layout. If 14/18 is inaccessible today, identify the last secure number range and use the next lesson to extend it one small step.

**Access and record:** Accept object arrangement, directed partner movement, drawing, speech, sign, AAC or eye gaze. Offer enlarged/tactile frames and numerals, and a spoken or tangible path. Record independent versus cued response, number range, strategy and the next specific teaching move. The assessment guidance in [assessment.md](assessment.md) draws on observations across the fortnight.