How to decrease the number - 500
by 4.2% of its value?
Value of Percentage Decrease. New Value
- A percentage value is nothing but a fraction with a denominator of 100:
- 4.2% = 4.2/100 = 4.2 ÷ 100 = 0.042
- ...
- To decrease a negative number, don't subtract from it, but add to it the 'Value of Percentage Decrease'.
- To decrease a positive number, subtract from it the 'Value of Percentage Decrease'.
- ...
Value of Percentage Decrease =
Percentage of the Decrease % × The original value =
4.2% × - 500
New Value =
The original value - Value of Percentage Decrease =
- 500 + (4.2% × - 500)
1. Calculate the End Value
decreased by a percentage of its Initial Value
End Value =
- 500 + Value of Percentage Decrease =
- 500 + (4.2% × - 500) =
- 500 + 4.2% × - 500 =
(- 500 is a common factor)
(1 + 4.2%) × - 500 =
(100% + 4.2%) × - 500 =
104.2% × - 500 =
104.2 ÷ 100 × - 500 =
104.2 × - 500 ÷ 100 =
- 52,100 ÷ 100 =
- 521
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 =
4.2% × - 500
The second method:
Value of Percentage Decrease =
The original value - New Value
Value of Percentage Decrease =
21
The end value: - 500 decreased by 4.2% percent = - 521
Value of Percentage Decrease = 21