You can solve this using an easy mathematical proportion:
you know that the car uses 20 gallons of fuel to travel 440 miles, so:
20 gallons : 440 miles = x : 1054 miles
The x is our unknown and stands for the fuel used to travel 1054 miles.
To solve it you should multiply the extreme knowns and then divide the result by the central known.
(20 gallons · 1054 miles) ÷ 440 miles
The unit miles cancel out so you're left with:
(21,080 gallons) ÷ 440 = 47.9 gallons ≈ 48 gallons
