Add and Subtract Fractions Common Denominator

To add or subtract fractions you must have

• Common numerators

• Common denominators

• Common multiples

• common factors

If we have common denominators and we want to add or subtract them we need to

• add/subtract the numerator and slide over the denominator.

• add/subtract the numerator and add/subtract the denominator.

38/50 + 7/50

• 45/100

• 26/50

• 45/50

• 81/100

36/40 - 24/40

• 60/80

• 12/0

• 12/40

• 12/20

What is 2/8 + 3/8 = ?

• 
• 
• 

5/10 + 1/10 = ?

• 10/10

• 6

• 3/10

• 6/10

4/6 - 1/6 = ?

• 5/6

• 1/12

• 3/6

• 5/12

7/7 - 5/7 = ?

• 
• 
• 
• 

What number could be a common denominator for these two fractions?
1/5   and   5/6?

• 30

• 11

• 6

• 5

What number could be a common denominator for these two fractions?
2/3   and   3/4

• 3

• 4

• 7

• 12