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1. Fractions
1/3 – 1/41 / +1 /
3 9 2/4 +/6
4/10 +1/5
1/4 – 1/5
½ + ¾ 1/4 +2/6
1 / +5/
7 7
1/ 3
2-2/
1/12 +1/7 4/5 +1/7 4/5 +1/6
3/4 +1/5 1/2 +1/9
6/7 +2/7

2. FRACTIONS
Numerator Denominator
Adding
Fractions

3. A FRACTION is a
number that
represents a part of
a whole.
1 Whole Cake
4 equal cut pieces of
cake equals 1 whole
cake. Those parts of the
cakes are a FRA CTION of
the cake. Home

4. Numerator
 The number on the top is called the numerator
 It represents the part of the whole number
The shaded
part
Numerator
1 is the
numerator
Whole number
2 These 2 equal parts
make the whole
Numerator
2
Whole number
6
Next
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5. Denominator
 The number on the bottom is called the denominator
 It represents the whole number
Part of the whole
1
Denominator
2 These 2 equal parts
make the
DENOMINATOR
Numerator
2
Denominator
5
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6. Adding Fractions with common
denominator
Is as simple as adding the 2 top
numbers (numerators) together
3 6 9
+ =
10 10 10

7. Adding Fractions with different
denominators
 Fractions with different denominators need to be made
READY first before they can be added together
 To get them READY you must find the common
denominator
 COMMON DENOMINATOR can be found by finding the
lowest common mulitple (LCM) of the two denominators

8. Finding the lowest common multiple
 The lowest common multiple of two numbers is the lowest
number in Both lists of multiples or the lowest number both
can be divided by
Multiples of 3 are 3,6,9,12,15,18.......
Multiples of 4 are 4,8,12,16,20,24....
1 1 .
So the lowest common multiple is 12
+
3 4

9. You can't add fractions
1/3 + 1/4 With different denominators
Turn both fractions into twelfths
For 3 to become a 12th you need to multiply it by 4
And for 4 to become a 12th you need to multiply it by 3
1 4 4 1 3 3
x = x =
3 4 12 4 3 12

10. Completing the Addition
1/3 = 4/12 AND ¼ = 3/12
4 3 7
+ =
12 12 12