Adding/Subtracting Fractions Unlike Denominator

What should be the Lowest Common Multiple/Denominator?

• 20

• 40

• 80

• 8

Answer explanation

40 is the smallest number you'll get when you skip count by 8 and also by 10.

What will your new fractions be, with your new common denominator?

• 4/40 + 5/40

• 28/40 + 12/40

• 28/40 + 15/40

• 7/40 + 3/40

Answer explanation

Since you multiplied 10x4, you also need to do 7x4 (=28).

Since you multiplied 8x5, you also need to do 3x5 (=15).

What will you get when you subtract these 9/12 - 4/12?

• 5/24

• 13/12

• 5/0

• 5/12

Answer explanation

Subtract the numerators. Keep the denominators.

• 1
• 3/6
• 1/2
• 2

Q1. How far is it to the nearest town?

• 3   3/4 miles

• 4 miles

• 4   3/4 miles

• 4 1/2 miles

2/6 + 1/2 =

• 5/6

• 3/6

• 4/6

• 3/8

8/9 - 5/6 = 

• 4/18

• 1/18

• 3/18

What must you have to add and subtract fractions?

• Common numerators

• Different numerators

• Different denominators

• Common denominators

• 1 7/8
• 2 1/8
• 3
• 6 3/8

1/18 + 5/6 = 

• 5/9

• 6/9

• 8/9