First make it a fraction 1 64/100. it would be over 100 because the 4 is in the hundreths place and the 1 is the 1 in "1.64" then simplify 64/100 down to 16/25 you do this by dividing both 64 and 100 by the same number until they can't be dived by the same number anymore. Then you'll have your answer, 1 16/25
