Yolanda needs 5 pounds of ground beef to make lasagna for a family reunion. one package of ground beef weighs 2 1/2 pounds. another package weighs 2 3/5
pounds. how much ground beef will yolanda have left over after making the lasagna?

You need to put the answers into improper fractions.
So 2 1/2 into 5/2 
And 2 3/5 into 13/5
Now your fractions need the same denominator so multiply 13/5 by 2 and multiply 5/2 by 5
You should now have 25/10 and 26/10
Now turn them back into mixed fractions.
2 5/10
2 6/10
2+2=4
5/10 + 6/10 = 11/10 OR 1 1/10
4+ 1 1/10 = 5 1/10
1/10 is your remainder