Transcript Fractions, Decimals and Percents

Lesson 3.1
Numbers can be written in both fraction and
decimal form.
For example: 3 can be written as 3/1 and 3.0
A fraction illustrates division 1/10 means 1÷10
1/10 in decimal form is .1
Fraction
7/10
1/100
19/100
1/1000 23/1000 471/1000
Decimal
Each decimal place has a name.
Tenths – the first number after the decimal
Hundredths – the second number after the decimal
Thousandths – the third number in the decimal
63.165
 Decimals
that have a definite number of
decimal places are called terminating
decimals.
 Examples:
 These
0.1, 0.25, 0.94
decimals always end.
 When
digits repeat themselves forever, they
are called repeating decimals.
 Examples
are: 0.333333, 0.754444, 0.121212
 Repeating
decimals have a bar drawn over
the digits that repeat.
 4/33
= 0.121212121...can be written as 0.12
 Patterns
can occur when we write fractions
in decimal form.
 Example:
1/99 = 0.01, 2/99 = 0.02,
15/99 = 0.15, 43/99 = __________
For fractions with a denominator of 99, the
digits in the numerator of the fraction are
the repeating digits in the decimal.
 If
I have a fraction with a denominator of 10,
the numerator is the decimal to the tenths
place.
 Example:
1/10 = .1
3/10 = .3
7/10 = ________
The decimal is a terminating decimal with one
decimal place (the tenths place)

If the fraction has a denominator of 100, the
numerator is the decimal to the hundredths
place.

Example: 26/100 = .26
72/100 = .72
39/100 = ________
If the fraction is less than 10/100, the first number
after the decimal is a 0.
Example: 7/100 = .07
9/100 = ____________

If the denominator is 1000, the numerator is the
decimal to the thousandths place.

Example: 576/1000 = .576
112/1000 = .112
423/1000 = _________
If the number is less than 100, the first number
after the decimal is a 0. Ex. 98/1000 = .098
If the number is less than 10, the first two
numbers after the decimal are 0. Ex. 8/1000 =
.008

What if I get a fraction without a 10, 100, or 1000?

First, ask yourself if the denominator can be changed
to a 10, 100, or 1000.
For example: 1/5
Can the denominator be changed to a 10?
YES! Multiply 5 x 2. Then, what you do to bottom, you
do to the top! Multiply 1 x 2. Your new fraction is
2/10...
What is the decimal value?
 Or
try this...
 20/50
– Can 50 turn into 100?
 YES!
Multiply 50 x 2 = 100, multiply 20 x 2 =
40. New fraction = 40/100...
 What
is the decimal value?
 Or
how about this?
 90/200?
 Multiply
 New
200 x 5 = 1000 and 90 x 5 = 450
fraction = 450/1000
 What
is the decimal?
 Find
equivalent fractions with denominators
of 10, 100 or 1000 for the following
fractions. Then, find the decimal value.
1)
6/20
2)
18/25
3)
40/50
4)
60/200
 9/40...I
cannot turn this into a fraction with
a denominator of 10, 100 or 1000...NOW
WHAT??
 Remember
 Yes,
long division??
you need to know how.

10/15

We cannot turn 15 into 10, 100 or 1000, so, set
up a long division question.

Remember, the 15 sits in the nook of the division
sign and the 10 sits under the lid.

15√10

15 cannot go into 10, so follow the steps of long
division to find your answer.
 Divisor
– a number by which a number is
going to be divided.
 Dividend
– the amount you want to divide up.
 Quotient
– the answer in a division question.
 http://www.wisc-
online.com/objects/ViewObject.aspx?ID=ABM
1001
 This
link will show you the steps of division.
 Try
converting these fractions to decimals
using long division.
 4/12
 6/15
 3/16
 Workbook
 Textbook
3.1
Page 88-90 #2,3,4,5,10,11,REFLECT