ratioProportion · Year 7 · Suggested learning sequence
Unit rate
A unit rate is the cost (or amount) for exactly one. If 3 pens cost $6, then one pen costs $6 ÷ 3 = $2. Finding 'how much for one' is always a sharing question, so it is a division: total cost divided by the number of items. The answer for one item is smaller than the total, so if your answer is bigger than the total you have multiplied by mistake. Once you know the cost of one, you can find the cost of any number by multiplying back up.
Sample questions
2 apples cost $10. How much does 1 apple cost?
- Share the total cost between the 2 apples.
- $10 ÷ 2 = $5.
- So 1 apple costs $5.
Answer: 5
2 erasers cost $10. How much does 1 eraser cost?
- Share the total cost between the 2 erasers.
- $10 ÷ 2 = $5.
- So 1 eraser costs $5.
Answer: 5
2 erasers cost $4. How much does 1 eraser cost?
- Share the total cost between the 2 erasers.
- $4 ÷ 2 = $2.
- So 1 eraser costs $2.
Answer: 2