A car averages 25 miles to the gallon. If a gallon of fuel costs $1.30, and you drive 1000 miles each month, how much does it cost to fuel the car for a year?

Let x equal what you are trying to find x ($ / yr)

Reciprocal factors
25 (mi / gal)
1.30 ($ / gal) 1000 (mi / mo) 12 (mo / yr) 1/25 (gal / mi)
1 / 1.30 (gal / $)
1 / 1000 (mo / mi)
/ 12 (yr / mo)

Build an equation
x ($ / yr) = 1.30 ($ / gal) * ins (gal / * 1000 (mi / ime) * 12 (me/ yr)
Multiply factors
x ($ / yr) = 624 ($ / yr)
Cost to fuel car for a year is $624.00.