A percentage is a ,[object Object],.

50% = 50100 = 0.5 = 12

[object Object],: 25%

• •Means 25 out of 100
• 25% = 25100 = 0.25
• In a class of 100 students, 25% = 25 students

To decimal

Divide by 100

• 35% = 35100 = 0.35
• 8% = 8100 = 0.08

To fraction

Write over 100, then simplify

• 50% = 50100 = 12
• 25% = 25100 = 14
• 75% = 75100 = 34

Find x% of a number

[object Object],: 20% of 150

• 20% = 0.20
• 150 × 0.20 = 30

[object Object],: 15% of 80

• 15% = 0.15
• 80 × 0.15 = 12

• 10% = divide by 10
• 50% = divide by 2
• 25% = divide by 4
• 75% = multiply by 3, then divide by 4

[object Object],: 10% of 60 60 ÷ 10 = 6

Discount

A $40 item with 25% discount:

• 25% of 40 = 0.25 × 40 = 10
• New price: 40 - 10 = $30

Tax

A $100 item with 15% tax:

• 15% of 100 = 0.15 × 100 = 15
• Total: 100 + 15 = $115

Increase

Original price: $50 Increase of 20%:

• 20% of 50 = 10
• New price: 50 + 10 = $60

Decrease

Original price: $80 Decrease of 30%:

• 30% of 80 = 24
• New price: 80 - 24 = $56