25 minutes · AC9MFN05 (practical subtraction and quantification); partial practice · educator review pending
Success: The child removes a named number from a starting set and counts what remains in the named place. Removed objects stay visible so the action can be checked.
Prepare per pair: ten counters, start mat, separate “taken away” tray, numeral cards and story cards.
- Retrieve, 3 min. Show a set of six and ask for its total. Point out that the set must be checked before changing it.
- Model, 6 min. Put six pretend passenger cards at a bus stop. Say, “Six are waiting here. Two leave this waiting area.” Move two to a separate tray. “I count the cards still waiting: four. The two that left are not counted as still at the stop.” Show the original six, action of two leaving, and four remaining.
- Guided game, 9 min. Partners try nine parcel cards with four moved to a shelf, five blocks with all five moved off a play mat, and eight clean-cloth cards with five moved to a box. Name the place whose remaining count matters. Swap roles.
- Fresh try, 4 min. Give seven objects on a mat. “Take away three to this tray. How many remain on the mat?” Observe without naming the result.
- Check, 3 min. Return the removed three and ask for the original total. Key: 6 − 2 = 4; 9 − 4 = 5; 5 − 5 = 0; 8 − 5 = 3; independent 7 − 3 = 4.
If the child includes removed objects in the remaining count: Point to the named mat and mark its boundary; count only inside it, then count all objects separately to show a different question. If the child says zero means the mat disappeared, show the empty mat beside numeral 0.
Access and record: Keep objects large and separated in tactile or high-contrast trays; provide a read-aloud/plain-text story, AAC/sign options and directed adult movement. Record start count, removed count, remaining count and whether the boundary was understood.