Download Dividing Decimals

Warm Up: Tuesday
1. 5.625 x 0.03
2. The average yearly rainfall in Houston is
3.5 inches. What is the total rainfall after
8.5 months?
Vocabulary Mapping
You will now be placed into small groups. I will
give you a SECRET WORD on a notecard. DO
NOT allow other groups to see your SECRET
WORD. You must do the following with it:
1- Write what it is (in your own words)
2- One example
3- Drawing/Picture representing your word
4- One non-example
Dividing
Decimals
Learning Objective:
I can divide
decimals by whole
numbers and by
decimals.
• You have $.90 and you are going to share
your money evenly amongst 6
people. How much will each person
receive?
• How did you figure that it would be $0.15
and NOT $15?
Remember the parts of a
division problem:
9
5 45
divisor
quotient
dividend
Dividing a Decimal by a Whole
Number
• Place the decimal point in the quotient
directly above the decimal point in the
dividend.
• Divide as you normally would
Example
2. 5
5 12.5
10
25
25
0
11. 28
9 101.52
9
11
9
25
18
72
72
Example 2
Dividing a Decimal by a
Decimal
• Move the decimal point in the divisor to the
right, until it becomes a WHOLE number.
• Move the decimal point in the dividend the
same number of places to the right that
you moved the decimal point in the divisor.
(Remember… what you do to one side, you
must do to the other)
Example
0.3 6.72
one space
03 67.2
New problem
22. 4
3 67.2
6
07
6
12
12
3.2 2.24
.7
32 22.4
22 4
0
Example 2
32
x5
160
32
x7
224
32
x8
256
Example 3
0.38 13.3
The decimal must be
moved 2 spaces to the
right.
When we move this one 2
spaces, we find that we
need to add a space. What
will we fill it with?
Answer: Fill it in
with a 0. 13.3
becomes 1330
SO, our problem becomes 038 into 1330. 038 is the
same as 38.
35
38 1330
114
190
190
0
38
x5
190
38
x3
114
38
x4
152
Example 4
2.48 1.3392
248 133.92
.5 4
248 133.92
124 0
9 92
9 92
0
248
x5
1240
248
x4
992
248
x6
1488
Terminating and Repeating
Decimals
• A terminating decimal is a decimal that
stops, or terminates.
• Examples: 1.25 or 0.892
• A repeating decimal is a decimal that has
a repeating digit or a repeating group of
digits.
• Examples: 1.3333… or .121212121…
• Repeating decimals usually have a bar
across the repeating portion.
2.3
7 .7 5
8 62.0 0
56
60
56
40
40
0
Terminating decimal
. 833
6 5.0 0 0
48
.83
20
18
20
18
2
This is a repeating decimal.
Reciprocal Teaching
Trenton makes $7.58 an hour. He
grossed $306.99 last week. How
many hours did he work?