Real-world examples of finding the whole amount using percentages

📚 Quick Study Guide

• 🔢 To find the whole amount when given a percentage and a part, we use the formula: $\text{Whole Amount} = \frac{\text{Part}}{\text{Percentage as a decimal}}$.
• ➗ First, convert the percentage into a decimal by dividing it by 100. For example, 25% becomes 0.25.
• 🍕 Then, divide the given part by the decimal you just calculated. This will give you the whole amount.
• 💡 Remember, the 'part' is a portion of the 'whole'. The percentage tells you what fraction of the whole the part represents.
• 💰 Real-world examples include calculating the original price of an item after a discount, determining the total sales when you know the commission earned, or finding the full cost of a meal when you know the tip amount.

Practice Quiz

1. A store is having a 20% off sale. If a shirt is on sale for $24, what was the original price of the shirt?

   1. $28.80
   2. $30.00
   3. $48.00
   4. $120.00

2. John received a 15% commission on his sales. If he earned $600 in commission, what were his total sales?

   1. $4,000
   2. $90
   3. $690
   4. $5,100

3. After adding an 8% sales tax, the total cost of a purchase was $108. What was the original price of the purchase before tax?

   1. $99.36
   2. $116.64
   3. $100
   4. $107.92

4. A student scored 80% on a test and got 40 questions correct. How many total questions were on the test?

   1. 32
   2. 50
   3. 48
   4. 60

5. A recipe calls for 30% sugar. If the recipe requires 75 grams of sugar, what is the total weight of all the ingredients in the recipe?

   1. 250 grams
   2. 22.5 grams
   3. 200 grams
   4. 150 grams

6. Sarah saves 12% of her monthly income. If she saved $360 this month, what was her monthly income?

   1. $3,000
   2. $43.20
   3. $4,320
   4. $2,640

7. A company spends 5% of its revenue on marketing. If the company spent $15,000 on marketing, what was its total revenue?

   1. $300,000
   2. $750
   3. $15,750
   4. $1,500,000