Student resources
Grades 5-9
How to Convert Units Step by Step
Unit conversions become easier when you ask whether the new unit is smaller or larger than the original unit.
Key ideas
- From a larger unit to a smaller unit, multiply.
- From a smaller unit to a larger unit, divide.
- Use a conversion fact such as 1 m = 100 cm or 1 kg = 1,000 g.
- Estimate first so you can catch answers that are too large or too small.
Multiply or Divide
| Situation | What to do | Example |
|---|---|---|
| Meters to centimeters | Multiply by 100 | 4 m = 400 cm |
| Centimeters to meters | Divide by 100 | 450 cm = 4.5 m |
| Kilograms to grams | Multiply by 1,000 | 6 kg = 6,000 g |
| Milliliters to liters | Divide by 1,000 | 750 mL = 0.75 L |
Practice questions
Should you multiply or divide to convert kilometers to meters?
Calculation: Meters are smaller than kilometers, so multiply
Answer: multiply
Convert 8 kg to g.
Calculation: 8 x 1,000 = 8,000
Answer: 8,000 g
Convert 300 cm to m.
Calculation: 300 / 100 = 3
Answer: 3 m
Why is 5 km greater than 5 m?
Calculation: 1 km = 1,000 m, so 5 km = 5,000 m
Answer: 5 km is greater