How to decrease the number - 11
by 30% of its value?
Value of Percentage Decrease. New Value
- A percentage value is nothing but a fraction with a denominator of 100:
- 30% = 30/100 = 30 ÷ 100 = 0.3
- ...
- 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 =
30% × - 11
New Value =
The original value - Value of Percentage Decrease =
- 11 + (30% × - 11)
1. Calculate the End Value
decreased by a percentage of its Initial Value
End Value =
- 11 + Value of Percentage Decrease =
- 11 + (30% × - 11) =
- 11 + 30% × - 11 =
(- 11 is a common factor)
(1 + 30%) × - 11 =
(100% + 30%) × - 11 =
130% × - 11 =
130 ÷ 100 × - 11 =
130 × - 11 ÷ 100 =
- 1,430 ÷ 100 =
- 14.3
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 =
30% × - 11
The second method:
Value of Percentage Decrease =
The original value - New Value
Value of Percentage Decrease =
3.3
The end value: - 11 decreased by 30% percent = - 14.3
Value of Percentage Decrease = 3.3