common denominators

 $\frac{2}{5}\ +\ \frac{1}{6}\ =$  

•  $\frac{17}{30}$  

•  $\frac{3}{11}$  

•  $\frac{12}{30}$  

•  $\frac{5}{30}$  

To add and subtract fractions, the fractions need to have a...

• common numerator

• common denominator

• common numerator and denominator

• mixed number

To find a common denominator you...

• add the denominators together

• skip count or list the multiples of each denominator until you find one they have in common

Solve.

³/₅ + ¹/₅ = ?

• ²/₁₀

• ²/₅
• ⁴/₁₀
• ⁴/₅

What is the least common denominator for

 $\frac{1}{2}\ and\ \frac{4}{7}$  

• 14

• 12

• 10

• 8

Could 8 be a common denominator for

 $\frac{1}{4}$  and  $\frac{2}{6}$  ?

•  No, because 8 is only a multiple of 4 but not of 6.

• Yes, 8 is a multiple of 4 and 6.
  

• I don't know!!

Which of these numbers could NOT be a common denominator for these two fractions?

 $\frac{2}{4}$   and  $\frac{3}{8}$  

• 32

• 12

• 8

• 16

Solve.

³/₆ - ²/₆ = ?

• ⁵/₆
• ¹/₆
• ¹/₀
• ⁵/₁₂

What is the least common denominator for

 $\frac{6}{10}\ and\ \frac{2}{6}$  

• 20

• 30

• 60

• 120

Solve.

⁵/₇ - ³/₇ = ?

• ⁸/₁₄

• ⁸/₇
• ²/₇
• ²/₀