In this math lesson we explore how to increase or decrease an amount by a given percentage – through simple multiplication.
The method for doing this type of percentage problem is as follows, where we find 35 increased by 20%.
First we start with the whole amount – in this case 35. Percentages describe a number expressed as a fraction of 100, so as 35 is the whole amount it is 100% or 100/100 or 1. To take off 20% we are taking off 20/100 or 0.2 of this – so 1 – 0.2 = 0.8.
0.8 of 35 is the same as 0.8 x 35 = 28.0.
Also see: Working Out Percentages On a Calculator
The post Percentage increase and decrease appeared first on Verandi.org.
source http://verandi.org/percentage-increase-and-decrease/
No comments:
Post a Comment