How to decrease the number 75
by 90% of its value?
Value of Percentage Decrease. New Value
- A percentage value is nothing but a fraction with a denominator of 100:
- 90% = 90/100 = 90 ÷ 100 = 0.9
- ...
- To decrease a positive number, subtract from it the 'Value of Percentage Decrease'.
- To decrease a negative number, don't subtract from it, but add to it the 'Value of Percentage Decrease'.
- ...
Value of Percentage Decrease =
Percentage of the Decrease % × The original value =
90% × 75
New Value =
The original value - Value of Percentage Decrease =
75 - (90% × 75)
1. Calculate the End Value
decreased by a percentage of its Initial Value
End Value =
75 - Value of Percentage Decrease =
75 - (90% × 75) =
75 - 90% × 75 =
(75 is a common factor)
(1 - 90%) × 75 =
(100% - 90%) × 75 =
10% × 75 =
10 ÷ 100 × 75 =
10 × 75 ÷ 100 =
750 ÷ 100 =
7.5
2. Value of Percentage Decrease
It can be calculated in two ways.
The first method:
Value of Percentage Decrease =
Percentage of the Decrease % × The original value =
90% × 75
The second method:
Value of Percentage Decrease =
The original value - New Value
Value of Percentage Decrease =
67.5
The end value: 75 decreased by 90% percent = 7.5
Value of Percentage Decrease = 67.5