Transcript Decimals

2-6 Decimals to Fractions and
vice versa
The relationship between fractions
and decimals
2
What fraction of the
rectangle is blue?
6
10
What decimal part of
the rectangle is blue?
.6
They
sound
alike!!!
To write a decimal as a fraction,
write the fraction as you would
say the decimal
Hundredths
Ten-thousandths
tenths
0.12345
Thousandths
Hundredthousandths
Say the decimal….Write it as a
fraction
•
•
•
•
•
.5
.65
.22
.2
.225
5
10
65
100
22
100
2
10
225
1000
Notice….when
you change a
decimal to a
fraction the
denominator is
always 10, 100,
1000 (powers of
ten!)
Is that all there is?
You have to simplify
the fraction if possible
Write .6 as a fraction
6
10
.6 =
3
5
6 Can be
10 simplified to:
3
.6 =
5
What about fractions to
decimals?
You can write a fraction as a decimal
by dividing the numerator by the
denominator…..the fraction symbol
means division!
3
4 3
4
.75
4 3.00
28
20
20
0
To make a
decimal…do the
division!
One more thing………
When you divide, REMEMBER, add
zeros to finish your division.
2 THINGS CAN
HAPPEN
1.) The division problem ends
2
 5 2  .4
5
Which is called A Terminating decimal
2
 6 2  .333333333333333.......
6
2.) or the division problem goes on
forever…. Which is called a Repeating
decimal
Repeating Decimals
A single digit might repeat….
.3333….
Or a group of digits might repeat…
.275275275….
Show repeating decimals by
placing a line over the digit or
group of digits that repeats
.33333…. Becomes .3
And
.275275….becomes .275
Remember
2
1
Will
be
1.4
5
2
1.2 will be 1
10
Simplified to:
Whole numbers stay the same!
1
1
5
Ordering Fractions and Decimals from least to greatest
4 , 0.93, and 0.9 from least to greatest.
5
Write as decimals with the same number of places.
4 = 0.80
0.93 = 0.93
0.9 = 0.90
5
Order
Graph the numbers on a number line.
0.93
0
0.2
0.80 < 0.90 < 0.93
0.4
0.6
0.8
1
Compare the decimals.
From least to greatest, the numbers are 4 , 0.9, 0.93.
5
Ordering Fractions and Decimals from least to greatest
4 , 0.93, and 0.9 from least to greatest.
5
Write as decimals with the same number of places.
4 = 0.80
0.93 = 0.93
0.9 = 0.90
5
Order
Can also treat it like money
0.80 cents < 0.90 cents < 0.93 cents
From least to greatest, the numbers are 4 , 0.9, 0.93.
5
Homework
Page 99 in your textbook….
Problems 8-36 even
Can use a calculator 