Download Multiplying Decimals

Module 5:
Multiplying
Decimals
The key to
multiplying
decimals is simply
knowing your
multiplication facts!
Step 1:
Multiply as if the
factors were whole
numbers
Step 1:
8.5 x 2.5=
85
X25
425
1700
Step 2:
Count the total
decimals moves in
EACH factors
8.5 x 2.5= 2 moves
total
Step 1:
8.5
X2.5
425
1700
2 1 2 5 next…..
Step 3:
Move the TOTAL
deci moves in the
product
Step 1:
8.5
X2.5
425
1700
2 1 .2 5
Try These:
1) 4.8
x 0.5
2) 3.55
x .05
Answers:
1) 4.8
x 0.5
48
x5
= 2.40
2 moves in product
2) 3.55
x .05
355
x 5
= 0.1775
4 moves in product
Lets practice
write each problem vertically
remember to move the total deci
moves for each FACTOR in your
PRODUCT
34.9 X 0.15
Basically it’s 349 x 15
Then deci in product 3 times
34.9 X 0.15
ANSWER
5.235
12.45 x 1.7
1245 x 17 = 21165 then move deci 3 times
from the left in your product
21.165
12.45 x 1.7
Answer
21.165
0.45 x 1.90
Count the total deci moves. Just multiply
45x19 then move deci moves in the
product
0.45 x 1.90
Answer:
0.855
3.05 x 1.65
Solve 305 x 165
Then move total
deci moves in the
product
3.05 x 1.65
Answer:
5.0325
Try These on your
own:
A)
B)
C)
D)
3.7 x 0.45
98.3 x 1.7
4.5 x 0.84
89.5 x 4.9
Answers:
A)
B)
C)
D)
3.7 x 0.45= 1.665
98.3 x 1.7= 167.11
4.5 x 0.84= 3.78
89.5 x 4.9= 438.55