I find it most intuitive to think in terms of larger intervals like Gallons Per 100 (or 1000) Miles. (Least amount decimal shifts and divisions, mostly just plus, minus and multiply.)
Conversion Table: GP100M to MPG in 0.5 gallon increments.
(GP100M = Gallons Per 100 Miles & MPG = Miles Per Gallon)
| GP100M | MPG
| -----GP100M | MPG
|
0.5 | 200.0
| 5.5 | 18.2
|
1.0 | 100.0 | 6.0
| 16.7
|
1.5 | 66.7
| 6.5 | 15.4
|
2.0 | 50.0
| 7.0 | 14.3
|
2.5 | 40.0
| 7.5 | 13.3
|
3.0 | 33.3 | 8.0
| 12.5
|
3.5 | 28.6 | 8.5
| 11.8
|
4.0 | 25.0 | 9.0
| 11.1
|
4.5 | 22.2 | 9.5
| 10.5
|
5.0 | 20.0 | | 10.0
|