Percentage and its applicatons

A unit that defines the word percent and explains the meaning of the percent symbol, and shows the relation between percentages and their equivalent fractions and decimals, giving a method for converting one form to the others. Four general types of problems are discussed: 1) finding a percent of a given number, 2) finding what percent one number is of another, 3) finding a number when a percent of it is given, 4) finding what percent greater or smaller one number is than another. The unit then applies the skills to consumer-related problems: sales tax and gratuities, discount, commission, simple interest, and compound interest. Sample problems with detailed solutions are illustrated, and problems to be solved by students are included.
E.g 5/10=50%
0.5=50%
20% of $400=$80
200/1000=20%
Decrease 20% of 100=80
A damaged chair that cost $110 was sold at a loss of 10%. =$110 x 1/10 = $11, loss.
=110 -11=99
A TV's actual price is at $1000, during the Great Singapore Sales, it was sold at a discount of 40%, what is the price now? =60/100x1000=600
A was handphone was priced at $100, it is taxed at 7%gst.What is the actual price of the pen?=$93

Is percentage important in our daily life???
Yes it is, obviously! For example, when a person with completely no knowledge of percentage, will surely be tricked by bad people when they say that they will give him a 50% discount, but in actual fact gave him only for example, 10&. The person will surely not know as he doesn't know how to calculate.
Also, when your boss ask you to calculate this month's profit or loss in percentage, you definetely be in a great headache!!!