25 minutes · AC9MFN03 (compare collections to 20 using counting and reasoning), AC9MFN01 (numeral support); partial practice · educator review pending
Success: The child decides more, fewer or same and justifies the relation by a count, one-to-one pairing or number path.
Prepare per pair: two mats, 40 counters, four ten-frames, cards 0–20 and the comparison strip.
- Retrieve, 3 min. Show 16 and 18 on the number path. Ask which comes later; later on the number path means a greater count for correctly counted sets.
- Model, 6 min. Place 16 counters on A and 18 on B. Count each. Say, “Eighteen is more than sixteen. If I pair one from A with one from B, two B counters remain.” Reverse the sentence: “Sixteen is fewer than eighteen.”
- Guided game, 9 min. Use pretend scenes from print-aids.md: 14 tray markers versus 18 pot markers, 20 cones versus 19 balls, then 16 seat cards versus 16 tickets. Children build, compare and show a reason. Change the spatial layout between examples.
- Fresh try, 4 min. Give 13 spread-out small counters and 17 close-together large counters. “Which has more? How do you know?” Do not give the totals first.
- Check, 3 min. Ask whether two different arrangements of 16 can have the same number. Key: 18 > 16 by two; 18 > 14; 19 < 20; 16 = 16; independent 17 > 13 by four.
If physical size or spread decides the answer: Count or pair the actual objects, then rearrange one set without changing its members. If “more” and “fewer” are reversed, name A and B separately and point to the direction of the sentence.
Access and record: Offer tactile boundaries, accessible objects, a spoken/tangible path and AAC more/fewer/same. A gesture showing four unmatched counters is a complete reason. Record relation, evidence, independent count and cues.