Session 25: Percentage

Intro Activity (75 minutes):

Begin with a question: "What does 50% off mean during a sale?" (15 minutes)

Explain the concept of percent as “per hundred” using real-life examples (e.g., discounts, grades, statistics).

Symbol: %

Example: 50% means 50 out of 100.

Why We Use Percentages?

1. Percentages help us compare things easily.
2. They're used in real life like:
3. Discounts in shopping (20% off)
4. Test scores (You got 80%)
5. Battery level (Phone at 30%)
6. Interest on money (Bank gives 5%)

Game Name: “Percentage Pop Quiz!”(20 minutes)

Objective: Warm up students with quick, fun percentage questions to activate prior knowledge.

Setup:

1. Divide the class into two teams.
2. Use flashcards or a whiteboard.
3. Each team takes turns answering questions.
4. One point for each correct answer.

Example Questions:

1. What is 50% of 100?     (Answer: 50)
2. What percentage is half of something?     (Answer: 50%)
3. Convert 0.25 to a percentage.       (Answer: 25%)
4. You got 8 out of 10 on a quiz. What’s your percentage?     (Answer: 80%)
5. What is 25% of 80?       (Answer: 20)
6. A pizza is cut into 4 equal slices. If you eat 1 slice, what percentage did you eat? (Answer: 25%)
7. Which is more: 40% or 3/10? (Answer: 40%)
8. True or False: 100% means the whole thing. (Answer: True)

This is an activity to see what students know. This should be done together after class.

Percentage Problems with Answers (40 minutes)

1. Finding a percentage of a number:
   Formula: Percentage of a number = Percentage/100 x number
   Example: What is 20% of 150?
   20/100 x 150 = 0.2 x 150 = 30
   
   
2. What is 20% of 150?
   30/20 x 100 = 1.5 x 100 = 150 
   
   
3. What is 25% of 200?
   Write the percentage as a fraction:
   25% = 25/100
   
   Multiply by the number:
   25/100 x 200 = 50
   
   Answer: 25% of 200 is 50
   
   
4. Ravi scored 72 marks out of 80 in a test. What percentage did he score?
   A: (72/80) × 100 = 90%
   
   
5. A shopkeeper gave a 20% discount on a ₹500 bag. What is the discount amount?
   A: 20% of ₹500 = (20/100) × 500 = ₹100
   
   
6. 3. A water tank is 75% full. If its total capacity is 200 liters, how much water is in the tank?
   A: 75% of 200 = (75/100) × 200 = 150 liters

Fraction to Percentage Conversion

Method: Multiply the fraction by 100 and add the percent symbol (%).

Examples:
1/2 × 100 = 50
3/4 × 100 = 75
2/5 × 100 = 40

Decimal to Percentage Conversion

Method: Multiply the decimal by 100 or move the decimal point two places to the right.

Examples:
0.5 = 50
0.25 = 25
0.875 = 87.5

Review Questions (5 minutes):

1. What does “percent” mean? Can you explain it with an example?

Follow-Up Task (10 minutes):

Home Work

1. A T-shirt is priced at ₹800. There is a 25% discount.
   • Discount amount?
     (25 ÷ 100) × 800 = ₹200
   • Final price?
     (₹800 − ₹200 = ₹600)
     
     
2. A water bottle has 1.5 L of water. 40% has been used.
   • Used water?
     (40 ÷ 100) × 1.5 = 0.6 L
   • Left?
     (1.5 − 0.6 = 0.9 L)

Expected Learning Outcomes:

Knowledge Building:

• Understand the concept of percentage
• Enhanced academic vocabulary

Skill Building:

• Speed and accuracy
• Critical thinking