Download Fractions and Decimals

Fractions and Operations with
Decimals
Today you will learn to:
• convert between fractions and decimals
• perform all four operations with decimals
M7.A.1.1.1
Warm-up Problem: Converting
Fractions to Decimals
Tammy is a registered nurse and is
about to get a raise at work. Her
raise is 9/16 of a dollar per hour. If
she currently makes $16.75 an
hour, what would her new hourly
wage be?
Converting
Fractions to
to Decimals
(A)
Converting
Fractions
Decimals
Instructions: Write the decimal equivalent beside each fractio
You can write a fraction as a decimal by dividing
the numerator by the denominator. A terminating
decimal is a decimal that stops, or terminates.
4
—
10
5
—
10
=
te thewithout
equivalent
beside
each fraction.
end,
the decimal
is a2repeating
decimal. The 3
3decimal
— = block can be one or—more=digits. You draw a —
repeating
8 above the repeating digit(s).
11
7
line
=
=
2
—
3
=
ting Fractions
to Decimals
(A)
If the same
block of digits
in a decimal repeats
2
1
—
—
3
6
=
=
5
4
—
—
10
6
=
=
11
—
12
=
—
—
—
Converting Decimals to Fractions
and Mixed Numbers
0.8
=
0.5454...
=
0.333...
=
0.3
=You—
= —
= or—
can write 0.3
a terminating
decimal as0.4
a fraction
mixed number by writing the portion of digits to the right
of the decimal point as a fraction.
0.714285... =
—
0.6
=
—
0.4545...
=
—
To compare and order fractions and decimals,
change all to either fractions or decimals (you decide which
0.08333...
= —
0.142857... = —
0.4
= —
is easier).
0.25
=
—
0.888...
=
—
0.8
=
—
Adding and Subtracting Decimals
RULE: When adding and/or subtracting decimals, be sure to
align the decimal points.
NOTE: If necessary, insert zeros at the end of each so that
each has the same number of decimal places.
2.310
19.100
+ 1.882
23.292
19.100
- 1.882
17.218
Warm-up Problem: Multiplying
Decimals
Iona’s favorite peaches are $2.50
per pound at the local farmers’
market. She bought 3.5 pounds of
the peaches. How much did she
spend?
Multiplying Decimals
RULE: Multiply the factors as if they were whole
numbers. Then, add the number of decimal places in
both factors to find the number of decimal places in
the product.
2.43
x 2.5
1215
4860
6.075
Dividing Decimals
NOTE: When dividing decimals, you may have to move
the decimal points.
NOTE: If necessary, you may need to add extra zeros to
the dividend.