How to decrease the number 4
by - 7.5% of its value?
Value of Percentage Decrease. New Value
- A percentage value is nothing but a fraction with a denominator of 100:
- - 7.5% = - 7.5/100 = - 7.5 ÷ 100 = - 0.075
- ...
- 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 =
- 7.5% × 4
New Value =
The original value - Value of Percentage Decrease =
4 - (- 7.5% × 4)
1. Calculate the End Value
decreased by a percentage of its Initial Value
End Value =
4 - Value of Percentage Decrease =
4 - (- 7.5% × 4) =
4 + 7.5% × 4 =
(4 is a common factor)
(1 + 7.5%) × 4 =
(100% + 7.5%) × 4 =
107.5% × 4 =
107.5 ÷ 100 × 4 =
107.5 × 4 ÷ 100 =
430 ÷ 100 =
4.3
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 =
- 7.5% × 4
The second method:
Value of Percentage Decrease =
The original value - New Value
Value of Percentage Decrease =
- 0.3
The value of the decrease is negative, so we are actually dealing with a Percentage Increase.
The end value: 4 decreased by - 7.5% percent = 4.3
Value of Percentage Decrease = - 0.3