Download Multiplying Decimals

Multiplying Decimals
Objectives
• Objective: We will find the product of
two decimals.
• Language Objective: We will use key
words whole number, product, and
decimal.
Vocabulary
Word
Definition
Example
a counting number
from one to infinity
7
95
489
decimal
a number written as a
whole number and a
part of a whole
number
4.2
four and two tenths
5.73
five and seventy-three
hundredths
product
the answer to a
multiplication problem
9 x 6 = 54
whole number
Steps for Multiplying Decimals
1. Line up the decimals as if they were whole
numbers. (You DON’T have to line up the
decimal point!)
2. Multiply as if the numbers were whole
numbers.
3. Go back to the decimal and count the
total number of decimal places to the right
of the decimal points.
4. Move the decimal point that many places
to the left of the product.
Multiplying Decimals
9.52 x 3.8
36.176
Multiplying Decimals
13.2 x 5.45
71.94
Multiplying Decimals
1.24 x 8
9.92
Multiplying Decimals
0.003 x 6.4
0.0192
Multiplying Decimals
7.49 x 1.02
7.6398
Multiplying Decimals
1.93 x 3.7
7.141
Multiplying Decimals
4.351 x 7.25
31.5375
Multiplying Decimals
2.45 x 2.81
6.8845
Multiplying Decimals
6.892 x 41.34
284.91528
Word Problems
Marty runs tract at Mountain View High School
in Tucson. He ran the 200-meter dash in 35.2
seconds. It took Jenny 1.2 times as long as
Marty to run the 200-meter dash. How long did
it take Jenny to run the 200-meter dash?
42.24 seconds
Word Problems
Zach bought 5.5 pounds of oranges for $0.90
per pound. How much did Zach spend on
oranges?
$4.95
Word Problems
Kara weighs 74.6 pounds. Her mom weighs 1.8
times as much as she does. How much does
Kara’s mom weigh?
134.28 pounds
Word Problems
Mary is buying candy for her birthday party.
She bought 3.2 pounds of gummy bears for
$1.25 per pound. She bought 5.75 pounds of
M&Ms for $4.50 per pound. She bout 2.8
pounds of licorice for $2.99 per pound. How
much money did Mary spend in all?
$38.25
Conclusion
What is the most important thing to remember
when multiplying a whole number and a
decimal?
How is this different from adding decimals?