Goal: connect 106–110 and explain 109 + 1 = 110 without changing the total during exchange. Prepare: hundred square, ten singles, one ten-strip, Day 24 cards.
- Notice, 3: Build 106 and 107 from the hundred plus loose pieces; ask which amount grows and where the numeral changes.
- Model, 5: Build 109, add one, count ten loose ones, trade them for one full ten. Show one hundred + one ten + zero ones = 110. Contrast 110 with 101 using the tens and ones columns.
- Guided, 8: Cards A/B start at 107 and 109. Learners count from 107 to 110 with three one-steps, then show 110 as 11 verified tens and as a hundred plus one ten. Keep the chart visible for order, but require a quantity explanation.
- Independent, 6: Card C is a schematic of 110. Learner represents it in two ways, changes it to 108 by removing two loose ones from an unexchanged 100 + 10 ones model, and describes the needed trade-back. Alternatively start at 110 and trade the one ten for ten singles before removing two.
- Exit, 3: Ask for one more than 109 and one less than 110. Key: 110 and 109. If 101 is named, align 110 and 101 above the mat and compare their ten and one columns.