Teacher copy: This page may include teaching prompts or answer keys. Answer keys in this public library can be viewed by anyone. Give learners a clean prompt, use checks as formative evidence, and change a case locally when prior access matters.
Invite: What should one total tell a pretend user?
Encounter/model: Moon-sticker tray: SET1, ADD2, SHOW gives3. ADD2 again gives5; SET2 instead replaces the total with2. This is an unperformed model, not real stock data.
Own practical action: Choose an invented collection/puzzle purpose and one check, such as “the start is included once”. Create your own SET and SHOW, run, then choose an ADD/change and predict. No complete model is entered for the child.
Observe/check: Ask what the start and total mean; inspect the actual chosen block and run if available.
Possible misconception: Thinking SET and ADD both mean putting another amount in. Compare before/after rather than demand a definition.
Next teaching move: Return to one SET/ADD contrast with their own values.
Use: choose one route, one model or neither where unnecessary. No30-route log or all-context quota. Home/extra 1 is an independent free offer, not required catch-up.