Answer: 18 cookies
Explanation:
Tara invites 6 friends, each friend gets 5 cookies.
So, 6 x 5 to find how many cookies are for 6 friends.
6 x 5
= 30 cookies
Tara only has 12 cookies. How much more does she need?
Everyone should get 30 cookies, but there is only 12.
Subtract to find the difference!
30-12=18