Day 18 · Open a ten bundleYear 2 Maths · T1 W3–4 · Day 18 lesson

Codes: AC9M2N01, AC9M2N02. Goal: exchange one ten for ten ones and show two equivalent forms. Prepare: 3 hundreds, 7 tens, 12 ones, mat.

1. Invite · 2. Build 372 and ask, “Can I make more loose ones without adding anything?”
2. Model · 5. Replace one of seven tens with ten ones. Count 3H 6T 12O, then check 300 + 60 + 12 = 372. Say “12 ones is allowed in a regrouped form; the usual numeral still has 2 in its ones place.”
3. Guided · 6. Build 324 and ask learners to direct the ten-to-ones exchange. Check 3H 1T 14O = 324. Return to standard grouping to show reversible exchange.
4. Choice · 6. Choose D18-A/B/C; ask for a drawn or physical exchange and a total check.
5. Exit · 4. Ask if 4H 6T 12O and 4H 7T 2O are equal. Expected yes, both 472; ask which ten was opened. If not, count ten loose ones into one strip.
6. Note · 2. Record model and language separately; a correct total with no exchange reasoning needs a next step.

Access/home/extension: Pre-draw ten dots on strips to reduce cutting; adult moves pieces at learner direction. Extension: show 372 a third way after opening one H as well.