Transcript Fractions - Johnston County Schools

Fractions
BY: JEFFREY MCAVEN
Parts of a Fraction
The top number of a fraction is
the numerator.
The bottom number of a
fraction is the denominator.
3
4
Multiplying and Dividing Fractions Rules
1.
2.
3.
4.
5.
Change all Mixed numbers to Improper Fractions
(MAD)
For all division problems KCF
Cross Reduce (or Cross Cancel) - Optional
Multiply straight across
Simplify if possible
MAD – Used to change Mixed Numbers to
Improper Fractions
MAD – Multiply/Add/Put over the Denominator
4+1=5
Add
=
Multiply
Put over the Denominator
2*2=4
Integer Rules:
+
SS = Add KSS
DS = Sub KSLN
K-C–C
×
÷
SS
DS
P
N
Reciprocal
To find the reciprocal of a fractions, flip it!
You need the reciprocal when dividing fractions!
EXAMPLES:
2
3
2½
3
2
=
5
2
2
5
Your Turn
Change the following into Improper Fractions.
1. 3 ½
2. 5 5/8
1/
3. 12
3
4. 15 ¾
Change the following into Mixed Numbers.
1.
40/
13
2.
100/
3.
4/
4.
9/
9
3
2
Answers
Change the following into Improper Fractions.
1.
7/
3 ½
=
2. 5 5/8
=
45/
3. 12 1/3
=
37/
4. 15 ¾
=
63/
2
8
3
4
Change the following into Mixed Numbers.
1.
40/
=
3
2.
100/
=
11
1/
3.
4/
3
=
1
1/
4.
9/
2
=
4
13
9
1/
13
9
3
½
Lets Look at Some Problems
 Multiplication
 Division
What to do when there is a Whole Number
Your Turn =)
1.
- 6 divided by 3 ½ =
7.
- 1/2
x
4/
5
=
2.
4/
5
divided by 2/5 =
8.
4/
5
3.
1 ½ divided by 3 ¾ =
9.
2 1/2 x 5 =
4.
3 ½ divided by - 1 ¾ =
10.
5 1/3 x -3 3/4 =
5.
2 ½ divided by
11.
7 2/3 x 1 1/2 =
6.
- 5 1/3 divided by
12.
-4 x 4 3/8 =
2 ½=
4/
9
=
x 10 =
Answers
1.
- 6 divided by 3 ½ =
-1
2.
4/
5
3.
1 ½ divided by 3 ¾ =
4.
5/
7
divided by 2/5 = 2
7.
- 1/2
x
4/
5
- 2/5
=
8.
4/
5
9.
2 1/2 x 5 =
3 ½ divided by - 1 ¾ = - 2
10.
5 1/3 x -3 3/4 = -20
5.
2 ½ divided by
11.
7 2/3 x 1 1/2 = 11 1/2
6.
- 5 1/3 divided by
12.
-4 x 4 3/8 =
2/
5
2 ½= 1
4/
9
= - 12
x 10 =
8
12 1/2
-17 1/2
Adding and Subtracting Fractions
Parts of a Fraction
The top number of a fraction is
the numerator.
The bottom number of a
fraction is the denominator.
3
4
Adding and Subtracting Fractions Rules
Change all Mixed numbers to Improper Fractions
(MAD)
2. Check to see if your fractions have common
denominators/ if not find common denominators.
3. Add or Subtract from left to right (only top)
4. Simplify if possible
1.
Integer Rules:
+
SS = Add KSS
DS = Sub KSLN
K-C–C
×
÷
SS
DS
P
N
Remember MAD
MAD – Multiply/Add/Put over the Denominator
4+1=5
Add
=
Multiply
Put over the Denominator
2*2=4
Lets Practice
Your Turn =)
Answers