Addition of fractions 
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1. Addition of fractions with the same denominator.
We have one piece of cake (1/5) and we add 2 pieces (2/5). Finally we have three pieces (3/5).
To add fractions with the same denominator, we must add the numerators, keeping the same denominator.
Examples: 2/7 + 3/7 + 1/7 = 6/7; 5/9 + 8/9 = 13/9
Solve these sums:
2/7 + 3/7 = 

3/5 + 1/5 = 

1/4 + 3/4 = 

3/8 + 1/8 + 2/8 = 
2. Addition of fractions with different denominators.
First, we must reduce the two fractions to a common denominator: 1/2 + 1/4 = 4/8 + 2/8
Then, we sum 4/8 + 2/8 = 6/8
To add fractions with different denominators, we must reduce them to a common denominator and then, we must apply the previous rule.
Do these sums:
1/2 + 1/3 = 

1/3 + 1/4 = 

1/2+2/3+3/4= 

1/3 + 1/6 = 
3. Addition of mixed numbers
To add mixed numbers, we add the whole numbers and the fractional parts.
Examples 3 1/3+ 2 1/3 = (3 +2) and (1/3 + 1/3) = 5 2/3 1 1/4 + 2 1/3 = (1 +2) + (1/4 +1/3 = 3/12 + 4/12) = 3 7/12.
Do these sums of mixed numbers. Do it on paper and check it.
3 y 3/5 + 2 y 1/3 = 

2 y 1/3 + 1 y 1/5 = 

7 y 1/4 + 6 y 1/3 = 

3 y 1/9 + 2 y 1/7 = 
4. Simplified fractions.
If we divide the numerator and the denominator of a fraction by the same number, we obtain a simplified fraction.
Examples: 6/15 = 6:3 / 15:3 = 2/5; 8/12 = 4/6 = 2/3, 9/12 = 3/4.
Simplify these fractions:
6/8 = 

3/12 = 

9/18 = 

3/18 = 
5 Add these fractions and simplify the result.
Do these operations on a paper.
Recuerda que 2/2 = 3/3 = 4/4 = 1
1/4 + 3/4 = 

3/8 + 1/8 = 

1/2 + 1/4 = 

1/6 + 1/6 = 
6 Do these problems
Do it on a paper and check it:
1. On Monday a worker won 8 1/3 euros and on Tuesday he won 9 2/5 euros. How much money did he win on both days? 

2. John has 1/3 of a cake and Montse has 1/5. How many pieces of cake did they have in total? 

3. Ana has 5 2/5 euros and Arturo has 6 1/4 euros. How much money do they have in total? 

4. A boy drinks ½ sip of a bottle and then he drinks 1/3. How much did he drink in total? 
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