Post on 03-Dec-2014
description
Adding Fractions
+
+ =
+ =
+ =
4
3
+ =
4
3+
+ =
4
3
4
1+
+ =
4
3
4
1+ =
+ =
4
3
4
1+ =
4
4
+ =
4
3
4
1+ =
4
41
Same denominators: add the numerators!
+
+ =
+ =
+ =
+ =
8
5
+ =
8
5+
+ =
8
5
8
2+
+ =
8
5
8
2+ =
+ =
8
5
8
2+ =
8
7
+ =
8
5
8
2+ =
8
7
+ =
8
5
4
1+ =
8
7
If the denominators are different, find equivalent fractions, then add numerators
+
+12
5+3
1
+12
5+3
1
+
+
12
5+3
1
+
+
12
5+3
1
+
+
12
5+3
1
+
+
12
5+3
1
12
5
+
+
12
5+3
1
12
5+
+
+
12
5+3
1
12
5+12
4
12
5+12
4
12
5+12
4=
12
5+12
4
12
9=
12
5+12
4
12
9= =
12
5+12
4
12
9= =
4
3
1. Check denominators
1. Check denominators
2. Find equivalent fractions so denominators same
1. Check denominators
2. Find equivalent fractions so denominators same
3. Add numerators
1. Check denominators
2. Find equivalent fractions so denominators same
3. Add numerators
4. Cancel down if needed
1. Check denominators2. Find equivalent fractions so
denominators same3. Add numerators4. Cancel down if needed5. Pull out the whole numbers
if needed
Your turn…
10
3
5
2
4
3
8
7
10
7
10
3
10
4
10
3
5
2
4
3
8
7
10
7
10
3
10
4
10
3
5
2
8
51
8
13
8
6
8
7
4
3
8
7
Sometimes, you have to change both denominators…
5
4
4
3
5
4
4
3
5
4
4
3
You need a number that is a multiple of both 4 and 5…
5
4
4
3 =
20
?
20
?
5
4
4
3 =
20
?
20
?
=20
16
20
15
5
4
4
3 =
20
?
20
?
=20
16
20
15 =
20
31
5
4
4
3 =
20
?
20
?
=20
16
20
15 =
20
31=20
111
1. Check denominators
1. Check denominators
2. Find ‘common denominator’ (LCM)
1. Check denominators
2. Find ‘common denominator’ (LCM)
3. Add numerators
1. Check denominators
2. Find ‘common denominator’ (LCM)
3. Add numerators
4. Cancel down if needed
1. Check denominators2. Find ‘common
denominator’ (LCM)3. Add numerators4. Cancel down if needed5. Pull out the whole numbers
if needed
Your turn…
4
3
6
1
3
2
4
1
12
11
12
8
12
3
3
2
4
1
4
3
6
1
12
11
12
9
12
2
4
3
6
1
12
11
12
8
12
3
3
2
4
1
Sometimes, you have to add fractions larger than one…
3
21
2
12
I suggest making these fractions ‘top heavy’.
3
11
2
12
3
11
2
12 =
3
4
2
5
3
11
2
12 =
3
4
2
5
6
8
6
10=
3
11
2
12 =
3
4
2
5
6
8
6
10=
= 6
18
3
11
2
12 =
3
4
2
5
6
8
6
10=
= 6
18= 3
Now find an exercise in the book or a work-sheet and practice!