Percentages Flashcards
What is the basic formula for finding a percentage?
% = part/whole x 100
What is the formula for percentage change?
(new value - old value / old value) x 100
How do you calculate percentage increase?
(increase/original value) x 100
How do you calculate percentage decrease?
(decrease/original value) x 100
What does a 10% increase mean in practical terms?
A 10% increase means adding 10% of the original value to the original value.
How do you reverse a percentage increase?
If a value is increased by a percentage, divide the new value by
(1 + % asadecimal)
For example, if a value increased by 20%, divide by 1.2
How do you reverse a percentage decrease?
If a value is decreased by a percentage, divide the new value by (1 - % asadecimal)
For example, if a value decreased by 20%, divide by 0.8
1% of 200
0.01 × 200 = 2
10% of 200
0.1 × 200 = 20
15% of 200
0.15 × 200 = 30
25% of 200
0.25 × 200 = 50
50% of 200
0.5 × 200 = 100
75% of 200
0.75 × 200 = 150
100% of 200
1 × 200 = 200
