You can find imprimatur by it being professionally processed and then proof of work being professionally edited
To test whether it's a factor:
-- Divide the big number by it. 81 / 6 = 13.5 .
-- If the quotient is a whole number,
then the small number is a factor
of the big number. 13.5 is not a whole number.
-- If the quotient is not a whole number,
then the small number is NOT a factor
of the big number. 6 is NOT a factor of 81 .
20 quarts equal 5 gallons. There are 4 quarts in a gallon so:
4 x 5 = 20