Divide the whole portion to be shared (5/8 gallon) by the number of portions (7).
=5/8 ÷ 7
to divide fractions, multiply by the reciprocal/inverse of 7
=5/8 * 1/7
multiply numerators; multiply denominators
=(5*1)/(8*7)
=5/56 of a gallon
ANSWER: Each person would get 5/56 of a gallon (or 0.089 of a gallon).
Hope this helps! :)