Codes: AC9M2N01, AC9M2N02. Goal: compare and order three-digit numbers using place value and a number line. Prepare: cards 318, 381, 308, 329 and a long blank strip marked 300 and 400.
- Invite · 2 min. Ask: “Which is larger, 318 or 381? Tell me why without counting to either one.”
- Model · 5 min. Align 318 and 381 in the mat. Say: “Both have 3 hundreds. Now I compare tens: 1 ten versus 8 tens. So 381 is larger.” Put 318 near 300 and 381 nearer 400 on the strip; placements are approximate within the interval.
- Guided compare · 6 min. Compare 318 and 308. Name equal hundreds, then 1 ten versus 0 tens. Ask learners to put 329 between 318 and 381; have them justify tens and ones.
- Partner order · 7 min. Pairs arrange
308, 318, 329, 381from least to greatest and place them on the number strip. One reads the order, another points to the first different digit in each neighbour comparison. Reorder the cards and repeat without copying. - Life example · 3 min. “The class has counted 329 recycled sheets; another class counted 318. Which stack count is greater, and by how many? Today explain which and why; the difference can wait.” Do not imply a count was actually collected.
- Check · 2 min. Everyone circles the larger of 309 and 390 and points to the deciding place. Focus learners explain. If ones dominate their choice, rebuild both and compare tens first.
Access routes: floor-sized number strip, desk strip, tactile tick marks or spoken ordered choices. Position alone is not the only proof; ask for place-value reasoning.