Codes: AC9M7N04. Goal: connect a familiar fraction, decimal and percentage as equivalent rational quantities. Prepare: 100-square sketch or folded strip, 1/2, 0.5, 50% cards.
- Launch · 3 min. Say: “A battery icon at half, a race at 0.5 of its route, and 50% of a playlist may point to the same share. What does ‘same’ mean here?” These are invented contexts; compare the proportion, not units.
- Model · 4 min. Shade 50 of 100 equal cells. Say: “50/100 simplifies to 1/2; 50 hundredths is 0.50 or 0.5; per hundred is 50%.” Put all three labels at the halfway mark on 0–1.
- Guide · 6 min. Shade 25/100, rename
1/4 = 0.25 = 25%; then 75/100, rename3/4 = 0.75 = 75%. Ask why 0.25 and 25% are related but not written with the same symbol. - Choose and justify · 7 min. Pairs match nine shuffled cards for the three quantities. One explains using equal parts or hundredths; the other checks with the strip, then they swap. For a challenge, locate 10%=0.1=1/10.
- Use a domain · 3 min. “A fictional phone download is at 75%. Is it three quarters complete?” Yes, under the usual 0–100% indicator. Ask what the whole is (the download).
- Exit · 2 min. Everyone gives two other forms of
1/4. Listen to focus learners' explanation of the whole. If a child says 0.4, return to 25 of 100 cells.
Access: tactile 4-part strip, readable high-contrast labels, spoken or AAC matching; offer the same representations in text for screen readers.