VidaaraPlay
Door 9 · Grade 5

🔢 Percentages

% means "out of 100"

▶ Play Door 9

Understanding Percent as "Out of 100"

What is Percent?
Percent means "per hundred" (cent = 100 in Latin). The symbol % means "out of 100."
• 50% = 50 out of 100 = 50/100 = ½
• 25% = 25 out of 100 = 25/100 = ¼
• 100% = all of it = 1 whole

Real-Life Examples:
• "I got 90% on my test" = answered 90 out of 100 correctly
• "This shirt is 20% off" = save 20 for every100
• "75% of students like pizza" = 75 out of 100 students

Worked example

Problem: What percent is shaded if 45 out of 100 squares are shaded?

  1. Percent = (part/whole) × 100
  2. Part = 45, Whole = 100
  3. 45/100 × 100 = 45%
  4. Answer: 45%

Answer: Answer: 45%

Converting Between Fractions, Decimals, Percents

The Conversion Triangle:
PERCENT
%
↗ ↖
/ \
FRACTION DECIMALConversion Rules:
FromToMethodPercentFractionPut over 100, simplifyPercentDecimalDivide by 100FractionDecimalDivide numerator by denominatorDecimalPercentMultiply by 100DecimalFractionWrite decimal as fraction, simplifyFractionPercentConvert to decimal first, then ×100

Worked example

Problem: Convert (3)/(5) to percent

  1. Method A: (3)/(5) = 0.6, 0.6 × 100 = 60%
  2. Method B: (3)/(5) = 60/100 = 60%
  3. Answer: 60%

Answer: Answer: 60%

Finding Percent of a Quantity

Three Methods to Find Percent of a Number:
Method 1: Convert to Decimal
• 20% of 60 = 0.2 × 60 = 12

Method 2: Use Fraction
• 20% = (1)/(5), so (1)/(5) of 60 = 12

Method 3: Use Proportion
• 20/100 = x/60
• Cross multiply: 100x = 1200, x = 12

Real-World Applications:
• Sales tax: 8% tax on 50 = 0.08 × 50 =4
• Tips: 15% tip on 40 = 0.15 × 40 =6
• Discounts: 25% off 80 = 0.25 × 80 =20 saved

Worked example

Problem: Find 15% of 200

  1. Decimal: 0.15 × 200 = 30
  2. Fraction: 15/100 × 200 = 3000/100 = 30
  3. Answer: 30

Answer: Answer: 30