Answer: 3.31 means 3 and 31 hundredths. Since 31 and 100 has no GCD (other than 1), it is already in simplest form. Thus, the answer is 3 31/100.
Step-by-step explanation: Decimal places are fractions with powers of 10 as the denominator. Every decimal place is another power of 10 in the denominator (.3=3/10 or 3/10^1 ; .31 = 31/100 or 3/10^2 and so forth). As for simplifying decimal fractions: If you had the decimal fraction 3.32 = 3 and 32/100, the 32/100 would not be in simplified form because 32 and 100 have 4 as a common factor, which can thus be reduced to 8/25, giving 3 and 8/25 as the answer. 3.31, however, is 3 and 31/100, which cannot be simplified any further. Hope that helps.