The 4 steps
Word problems become easy with 4 steps: 1) Understand what is asked, 2) Plan which skill to use (coordinate, ratio or proportion), 3) Solve step by step, 4) Check your answer makes sense.
Key idea
For ratio problems, find what one part is worth, then multiply. For proportion, multiply or divide both amounts by the same number.
Two worked word problems
Worked example
A class has boys and girls in the ratio 2 : 3. There are 4 boys. How many girls are there? Plan: boys went from 2 to 4, so multiply by 2. Solve: girls = 3 × 2 = 6. Check: 4 : 6 simplifies to 2 : 3. Correct!
Worked example
3 oranges cost RM6. How much do 5 oranges cost? Plan: find the cost of 1 first. Solve: 1 orange = RM6 ÷ 3 = RM2, so 5 oranges = RM2 × 5 = RM10. Check: RM10 ÷ 5 = RM2 each. Correct!
Remember
- Read the question twice.
- Write down what you know.
- Always check your answer.