Download 3 8

with regrouping
First………let’s
remember this ……
How to change a mixed number to
an improper fraction
• Multiply the whole
number times the
denominator.
• Add your answer to the
numerator.
• Put your new number
over the denominator.
+1
4x =
2
9
2
Change this mixed number to an
improper fraction
• Multiply the whole
number times the
denominator.
• Add your answer to the
numerator.
• Put your new number
over the denominator.
+2 20
6x =
3 3
Change this mixed number to an
improper fraction
• Multiply the whole
number times the
denominator.
• Add your answer to the
numerator.
• Put your new number
over the denominator.
+ 2 17
3x =
5 5
Excellent!!!!
Let’s keep moving…….
Adding Mixed Numbers
Find the sum.
1
+
3
4
9
1. Rewrite the fraction using
LCD if denominators are
different.
1
2. Add or subtract the fractions,
4
9
5
9
then the whole numbers.
3. Simplify if possible.
In this problem, the denominators are the
same, so begin with step 2.
Let’s Do More Examples!
Find the sum.
1
+
3
4
4
4
9
1
3
7
9
X3
=
X3
3
9
+
5
7
8
X2
1
4
=
X2
8
9
9
10
2
8
1
8
= 1
1
8
Add the whole numbers.
Subtracting Mixed
Numbers
Find the Difference.
3
X4
12
- 1 5 = 20
X4
5
X6
18
=
3
4 X 6 24
1 17
20
= 1
20
4
3
1
X4
- 1 6
2
14
24
=
X4
=
7
2
12
4
24
7
12
10 7
8
-
4
6
1
8
6
= 3
4
8
6
3
4
Now You Try!
Find the sum or difference.
3 X2 6
5
10
3
=
4
=
10
5
12
6
X2
9
1
+ 7 10
- 1 12
10
15
10
= 1
5
10
11
=
1
2
9 =
12
3
1
2
3
3
4
3
4
What if I’m supposed to
subtract a larger fraction from
a smaller fraction?_________
_______________________
+
6 7 1
18
x
-
3
3
8
3
6 =
8
9
8
33
4
9
+
13
9
4
1
10 9
x
- 4 7
9
5
6
9
=
5
2
3
Can you regroup with unlike
denominators?
Sure, but first
find the LCD
and equivalent
fractions.
8
x7
9
Watch this!
-
5
3
2 14 35
1
3 x 7 21 21
x3
5 15
7 x 3 21
20
21
Let’s see that again!
Remember,
first find the
LCD and
equivalent
fractions.
Watch this!
5
x4
6
-
3
2
2 8 28
1
5 x 4 20 20
x5
3 15
4 x 5 20
13
20
How about these!
If you have a whole number, make a fraction
with 0 in the numerator and the same
denominator the mixed number has.
5
8
0
618
-
3
2
0
1
9 7
8
8
2
8
6
8
=
2
3
4
5
3
7
7
4
7
3
7
Then regroup as we have before!
Remember to simplify if you need to.
Now, you try!!!!
6 7
-
3
3
2 = 10
1
=1
8 8
4
3 3
=
8 8
7
8
9
-
10
4
5
4
12 = 30
1
6 = 18 18
7 = 14
9
18
16 =
18
5
8
9
Remember, you can also
convert each mixed number
into an improper fraction and
use the butterfly method.