25 minutes · AC9MFN01 (18–19 representation and order), AC9MFN03 (count and compare 18/19); partial practice · educator review pending
Success today: The child builds 18 and 19, counts each set, matches the numerals, and places 18 between 17 and 19.
Prepare per pair: two ten-frames, 19 counters, cards 17–19 and path; see print-aids.md. Keep the second frame orientation consistent.
- Reconnect, 3 min. Show 17 as ten and seven. Ask what one extra object would make; let the child test the idea.
- Model, 6 min. Fill ten spaces and eight more. Say, “This shows eighteen; I can see two empty spaces in the second frame. I will count to confirm.” Show
18. Add one object. “Now there is one empty space and nineteen objects.” Count and show19. Compare: 19 has one more object than 18. - Play: museum cases, 9 min. One partner arranges 18 pretend labels across two cases; another checks and chooses
18. Add one label for19, then swap. Variants: 18/19 bike-repair job cards or 18/19 weather-station marks. If a child invents a scene, keep the counts unchanged for the check. - Independent try, 4 min. Hand the child an uncounted pile of 19 objects and cards
17, 18, 19. “Make eighteen, choose its numeral, then show the next number.” Accept counting all or ten-and-more with a verification count. - Check and close, 3 min. Lay
17, [empty], 19. “Which card is missing? How do you know?” Key: 18;17, 18, 19is the order; 19 is one more than 18.
If the child infers 18 solely from two empty spaces: Ask them to verify that the first frame really holds ten and the second holds eight. An empty-space shortcut is only reliable if the frame and its filling are known. If 18 and 19 are reversed, place each beside its checked collection and compare the one extra object.
Access and record: Offer high-contrast or tactile cards, a raised second frame, hand-sized counters, spoken descriptions, and directed partner placement. Record total/count match for 18 and 19, missing-number reasoning, counting accuracy and prompt level.