CHAPTER 4

DECIMALS AND PERCENTAGE

-DECIMALS-

u DECIMALS ARE SEEN ALMOST EVERYWHERE

u THE USE OF DECIMALS IMPROVES THE DEGREE OF ACCURACY IN A MEASUREMANT

To read and write decimals to thousand

Decimals	Decimals read as
0.47	Zero point four seven
3.59	Three point five nine
4.073	Four point zero seven three
38.24	Thirty-eight point two four

SUMMARY

u Definition

u A decimals represents a fraction whose denominator is 10,100,1000,…

-PERCENTAGE-

u A PERCENTAGE IS A FRACTION OUT OF 100…

u THE WORD PERCENTAGE COMES FROM THE LATIN WORD ‘PER CENTUM’

TO FIND THE PERCENTAGE ONE NUMBER IS OF ANOTHER

To find one quantity as a percentage of another.

u 1.Make sure both quantities are changed to the same unit.

u 2.Form a fraction of one quantity over another.

u 3.Multiply the fraction by 100%.

To find a number given by using percentage

u 1.find the value of 1% of the number

u 2.find the value of 1000% of the number

Math Plus

u Following a decrease

u % final value = 100% - % decrease..

u Following an decrease…

u % final value = 100% + % decrease..

Summary

u Definition

u Percentage is a fraction out of 100

u Decrease may be discount or loss