# Home 21 · Choose a useful unit

**Try one tiny turn.**

Prepare: One familiar safe object or just its description; no printer needed.

Invitation: Ask one question about length, mass or capacity. Offer two suitable unit words and let the child choose a tool. Ask why it helps.

Adult worked model/check: A sealed packet mass would use g and a scale; a bookmark edge would use cm and a ruler.

Choice and boundary: Accept usual communication and stop after one choice. A label answer is not measuring.

Usual communication, exact scribing, private/untimed work and stopping are welcome. Keep a model answer separate from your child's own attempt; do not correct it silently. Observe one useful reason and choose a new unrelated example if wanted.

[Pick another home turn](../parent-start.md)