instruction:
You are provided with an arithmetic question. Your task is to compute the solution using the given arithmetic operations. The only arithmetic operators needed to answer the questions are'+'(addition) and'-'(subtraction). The answer should be correct to one decimal place.
question:
Mary found 2 seashells and Keith found 5 seashells on the beach.When they cleaned them, they discovered that 9 were cracked. Howmany seashells did they find together?
answer:
7.0


question:
A construction company ordered 0.16 ton ofconcrete, 0.14 ton of bricks, and 0.5 ton of stone. How many tons of material did the company order in all?
answer:
0.8


question:
Fred has 40 baseball cards. Keith bought 22 of Fred's baseball cards.How many baseball cards does Fred have now?
answer:

18.0