I hope that HELP you ok the answer is 16 because if you divide 28 ÷ 4 = 7 so you think about 4 oh and there is 1 too because 4÷1=4so it is two answer 1 and 16 it is 16 because if you divide 4 ÷16=4 so that is why but I say to be smart and to put 16 if I were you ok I hope that help