Neil has 3 partially full cans of white paint. They contain 1/3 gallon. 1/5 gallon and 1/2 gallon of paint about how many paint does Neil have in all?

About 1 gal

Step-by-step explanation:

When you are estimating with fractions, you should round them off to the closest integers that you can work with in your head.

⅓, ⅕, and ½ are all close to zero, but that's absurd, because Neil clearly has some paint.

Instead, let's estimate that ⅓ gal + ⅕ gal make about ½ gal.

They still have the other ½ gal, and

½ gal + ½ gal = 1 gal.

Neil has about 1 gal of paint.