# Day 35 — What happened to the set?

**25 minutes · AC9MFN05 (choose an addition, subtraction or unchanged-set representation); partial practice · educator review pending**

**Success:** The child listens to or reads a practical story, shows the action with objects and gives the result for the named set. No operation symbol is required.

**Prepare per pair:** ten counters, two trays, start/change/now mat and selected [change cards](print-aids.md). Keep the stories short and repeat the question after the action.

1. **Retrieve, 3 min.** Show four objects, then add one. Ask what happened and the new count. Reset, remove one and ask the same questions.
2. **Model, 6 min.** Say, “Five shape cards are in a tray. Two more are added. How many in the tray now?” Act out five plus two and count seven. Then say, “Seven are in the tray. Two are taken out. How many remain?” Act out seven taking away two and count five. Explain, “The action tells me what to do.”
3. **Guided game, 9 min.** Partners choose three different stories: 8 cones with 3 stored, 7 labels with 0 added, 4 bowls with 4 more, or 6 passengers with 2 leaving. They show start, action and named result; swap roles. Include at least one addition and one removal.
4. **Fresh try, 4 min.** Present two fresh stories separately: “Three books are on a trolley; four join.” Then “Nine cards are on a desk; two move to a shelf. How many remain on the desk?” The child models each without an operation cue.
5. **Check, 3 min.** Ask how a child can tell whether to add or take away in a new story. **Key:** 5 + 2 = 7; 7 − 2 = 5; 8 − 3 = 5; 7 + 0 = 7; 4 + 4 = 8; 6 − 2 = 4; fresh 3 + 4 = 7 and 9 − 2 = 7 on desk.

**If the child always adds the two spoken numbers:** Repeat the action with objects and ask which pieces remain in the named place. If a verbal story is too heavy, show start/action/now pictures or act it out before asking for the count.

**Access and record:** Offer plain-text/read-aloud cards, tangible objects, high-contrast/tactile mats, sign/AAC and directed partner placement. Record action selected, correct named set, result, strategy and cues. Use [assessment.md](assessment.md) for a follow-up check, not a speed grade.