25 minutes · AC9MFN01 review; AC9MFN03 · educator review pending
Success: Child represents zero with an empty bounded set, compares it with a nonempty set, and checks a near-twenty comparison or equality using counted objects. Saying 0 alone without an empty set is not enough evidence.
Prepare: C06 (A0/B8), C05 (A19/B20), and C10 (17/17) as an alternative; trays, counters, numeral cards 0, 8, 17, 19, 20. Check set A=0/B=6, then A=20/B=15 if ready.
- Retrieve, 3 min. Point to an empty A tray and ask, “How many counters are inside this boundary?” Accept zero and link it to
0. - Model, 5 min. Read C06. Pairing gives no pairs and eight B counters unmatched. Say, “A has zero; B has eight, so B has more.” Count B carefully; never call the empty tray “missing data.”
- Partner stations, 10 min. Pairs try C06 then C05, counting A19 and B20 and pairing to find one unmatched B. If needed, swap C05 for C10 equality and return to nineteen/twenty in a later small group. Teacher observes three learners' count across the teen sequence and use of
0. - Fresh check, 4 min. Start A empty and B six: child identifies 0/6 and relation. For learners ready for the stated scope, follow with a new A20/B15 layout and ask for a count and comparison; record each separately.
- Close, 3 min. Ask how “zero” differs from “not checked yet.” Key: C06 0/8 B more; C05 19/20 B more by one; C10 17/17 equal; fresh 0/6 B more, extension 20/15 A more by five.
If a child counts an empty tray as one: Keep the boundary visible and ask what object the word “one” would name; do not put an object in simply to cue the answer. Access and record: An empty tactile tray and numeral card can be explored by touch; child may use AAC or spoken response. Record which near-twenty set was actually checked, since zero work alone does not establish comparison to 20.