Solving measurement word problems
First make sure all the numbers use the same unit. Then decide whether to add, subtract, multiply or divide.
Key idea
Same units first! 1 m = 100 cm · 1 kg = 1000 g · 1 ℓ = 1000 mℓ
Four steps
1) Understand the story. 2) Plan the operation. 3) Solve carefully. 4) Check the answer.
Worked example
A rope is 2 m long. Amir cuts off 50 cm. How much is left?
Change to the same unit: 2 m = 200 cm. Then 200 − 50 = 150 cm.
Remember
- Change to one unit before you add or subtract.
- "How much left" usually means subtract.
- "In all" or "altogether" usually means add.