lesson
Choose the conversion factor
1 · Learn
One kilometre is 1,000 metres; one metre is 100 centimetres. Use the correct relationship for the units in your question.
To change larger units into smaller ones, more units are needed. A 3 km journey is 3,000 m. Always write the unit so the number has a clear meaning.
2 · Worked example
2 m 35 cm is 235 cm. I can then add 80 cm to get 315 cm, or 3 m 15 cm.
3 · Your turn
Convert 4 km to metres and 2 kg 250 g to grams. Find 1 m 40 cm + 75 cm.
Check your answer
4,000 m; 2,250 g; 215 cm or 2 m 15 cm.
4 · Apply your learning
Estimate a safe classroom length, measure it and record it in two equivalent units.
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