I'm assuming the 3.4's units are gallons, too. If you're rounding to the nearest <em>whole gallon</em>, that means you're going to have round 3.4 to the nearest <em>whole number. </em>Think about the two whole numbers 3.4 lies between: 3 and 4. Which one of those is 3.4 closer to? That's where you'll want to round.
absolute value is just the number disregarding whether it's positive or negative, and the only even number less than -12 that is still under -15 is -14
