Well, darling, if you want to get technical, 25 goes into 650 a total of 26 times. Simple division, nothing fancy. Just divide 650 by 25 and you'll get your answer. Math doesn't have to be complicated, honey.
50
325
650
650
625
25
625
650 miles divided by 25 miles per gallon = 650/25 = 26 gallons
25% of 650= 25% * 650= 0.25 * 650= 162.5
50
325
13
1015.3846
1857.1429
407
650