+ and - fractions with unlike denominators

• 5/4

• 3/4

Add 1/6 + 1/2=?

• 4/6

• 2/8

1/4 + 5/8

• 7/8

• 3/4

8/9 - 1/3 = 

• 5/9

• 2/3

1/4+1/4

• 1
• 1/2
• 2