Transcript Dividing Decimals

Dividing Decimals
Dividend (in the box)
Find the quotient of 12 ÷
Divisor (out of the box)
4
quotient
3
divisor dividend
Set it up
4 12
-12
0
Find the quotient of 156 ÷
12
13
12 156
-12
36
-36
0
Dividing a whole number by a
whole number
We are able to divide these numbers because the divisors
are whole numbers!
divisor
3
4 12
-12
0
divisor
13
12 156
-12
36
-36
0
Sometimes, we have to do a little
more…………………..
Dividing a whole number by a
DECIMAL
What if the divisor is NOT a whole number??
Example:
Set it up
The divisor is
NOT a whole
number!
156 ÷ 1.2
1.2 156
We have to change the divisor to a
whole number by moving the decimal
to the right (which is the same thing as
multiplying by a power of 10) (x 10, x
100, x 1000, etc.)
Dividing a whole number by a
DECIMAL
Example:
We have to change
the divisor to a
whole number by
moving the
decimal to the
right.
156 ÷ 1.2
1.2 156• 0 •
•
We had to
move the
decimal 1
place to the
right, to make
the divisor a
whole number
We have to move the
decimal the same
number of places in
the dividend also!
(1 place)
12. 1560.
Dividing a whole number by a
DECIMAL
130
12.
• Bring the decimal
1560. straight up to the
quotient.
-12
36
-3 6
0 0
- 0
0
Now, you are ready to
divide!
Now, CHECK IT
by multiplying!
130
X 1.2
260
+1 3 0 0
1 5 6•0
Dividing a DECIMAL by a DECIMAL
Find the quotient 1.56 ÷ 1.2
1•3
1.2• 156
. •
-12
36
-3 6
0
Bring the decimal
straight up to the
quotient.
Now, you are ready to
divide!
Now, CHECK IT
by multiplying!
1.3
X 1.2
26
+1 3 0
1•5 6
Dividing a DECIMAL by a DECIMAL
Find the quotient 15.6 ÷ .12
1 3 0•
.12• 15.6 0 •
-12
36
-3 6
00
-0 0
0
Bring the decimal
straight up to the
quotient.
Now, you are ready to
divide!
Now, CHECK IT
by multiplying!
130
X .12
260
+1300
1560
•
Dividing Decimals
• Change the divisor to a whole
number by moving the decimal
to the right.
• Move the decimal the same
number of places in the dividend
• If you don’t have to move the
decimal in the divisor, you don’t
move it in the dividend either!
• Bring the decimal straight up to
the quotient
• Divide
• Check your solution by
multiplying!