Pls help i dont understand im sped

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer

How many square centimeters of wrapping paper will be used to wrap the shoe box?

At the bulk food store, stacy bought 7 lbs of nuts. she used 8 ounces of nuts in a recipe and then put the rest of the nuts into small bags to use for snacks. if each small bag contains 4 ounces of nuts, how many small bags of nuts did stacy make? a, 26 b,24 c,19 d,15. show work first one , to you first user, okie welp