Adding fraction unlike denominators

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

• 3
• 4
• 7
• 12

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?
3/10   and   1/5

• 5
• 10
• 15
• These numbers do not have a common denominator

2/3 + 1/2 = 

• 6/7
• 2/6
• 3/5
• 7/6

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

What is the first step in solving this problem? 
⅘ + ½ =

• Add the top parts of the fraction
• Rewrite the fractions in the simplest form. 
• Find a common denominator. 
• Make each fraction into an improper faction. 

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2