Stretch: Converting Measurement Units with Ratios
I can use ratio reasoning and unit rates to convert measurements (feet↔inches, hours↔minutes, cm↔m).
🧠 The Challenge
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A conversion factor is a ratio equal to 1, like 12 in / 1 ft. Multiply by it to change units. Bigger unit → smaller unit means you multiply; smaller → bigger means you divide.
👀 Worked Example
Convert 5 ft to inches: 1 ft = 12 in, so 5 ft × (12 in / 1 ft) = 60 in. Convert 90 min to hours: 90 ÷ 60 = 1.5 h.
✏️ Your Turn
0 of 3 checks complete
1. 3 feet equals how many inches? (1 ft = 12 in)
2. 2.5 hours equals how many minutes? (1 h = 60 min)
3. 240 cm equals how many meters? (100 cm = 1 m)
💬 Explain Your Thinking
Explain how you convert 4 feet into inches:
"To convert 4 feet to inches I use 1 ft = blank in, so 4 × blank = blank inches."