One to One to 20

Watch: Watch whether the learner matches every card by symbol before entering a count. The decisive evidence is a complete one-to-one placement map plus the empty-pocket entry.

Misread: A learner who enters 5 or 6 is counting cards, filled pockets, or all pockets; a learner who names the Sun pocket has identified the unmatched target but not its number.

Curriculum: This task assesses one-to-one correspondence between finite sets, capacity-one matching, and counting the unmatched targets after a complete match.