Mario bought a 1-gal can of paint to paint his room. He used 0.5 gal for the first coat and 0.4 gal for the second coat. How much paint did he have left?
0.1 gal of Paint
If we want to know how much paint is left in the can , and a can started out with 1 gallon, and we know 0.5 gal was used (also known as being taken out of the can) and 0.4 gal more was used we can then set up the equation
So 0.1 gallons were left in the can.