Answer :

so eventhough you know the answer
the answer is to factor, make ones
another way is use calculator or long division

so factor and make 1's
exg 2/4=1/2 because 2/4=1/2 times 2/2 and 2/2=1 so 1/2 times 1=1/2 so

100=2 times 2 times 5 times 5
5=5
so 10/5=(2 ties 2 times 5 times 5)/5=(2 times 2 times 5)/1 times 5/5=(2 times 2 times 5)/1 times 1=(20)/1=20
the answer is 20