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