How to Use the Percent per Unit Method (With Examples)

The Percent per Unit Method is a helpful strategy for solving problems involving percentages, especially when you're comparing parts of a whole or working with ratios. It allows you to break down the percentage into a rate per unit and then multiply to find your answer.

What Is the Percent per Unit Method?

This method calculates the percentage value associated with one unit and then multiplies it by the desired number of units.

Percent per Unit Formula

Percent per Unit = Total Percentage / Total Units
Result = Percent per Unit × Number of Units

Example 1: Finding the Percentage for a Smaller Group

In a survey, 60% of 120 people like chocolate. How many people in a group of 40 would you expect to like chocolate?

  Percent per Person = 60% / 120 = 0.5%
  For 40 people: 0.5% × 40 = 20%
  So, 20% of 40 people = 20 people
  

Example 2: Sales Commission

A 10% commission is earned on $2,000 in sales. What is the commission per $1 sold, and how much for $500 in sales?

  Percent per Dollar = 10% / 2000 = 0.005
  For $500: 0.005 × 500 = 2.5%
  So, the commission is 2.5% of $500 = $25
  

Real-Life Uses

• Education: Estimate student performance in scaled assessments.
• Finance: Calculate partial commissions, discounts, or taxes.
• Science: Scale data across experiments or populations.
• Business: Compare performance metrics per employee or customer.

Practice Questions

1. 80% of 200 students passed an exam. How many would you expect to pass in a class of 50?
2. A store gives a 5% discount on $1,000. What is the discount per dollar, and how much would it be on a $300 purchase?
3. If 25% of 40 apples are bad, how many bad apples would be in a batch of 120?

Answers:

• Percent per student = 80% / 200 = 0.4% → 0.4% × 50 = 20%
• Discount per dollar = 5% / 1000 = 0.005 → 0.005 × 300 = 1.5% = $15
• Percent per apple = 25% / 40 = 0.625% → 0.625% × 120 = 75%

Summary

The Percent per Unit Method helps you scale percentages across different amounts easily. It's a flexible and logical way to solve a wide range of problems, especially when comparing groups or finding partial values.

Percent per Unit = Total Percent / Total Units
Result = Percent per Unit × Target Units

Try this method whenever you're dealing with proportional thinking or estimating outcomes across scaled quantities.