Firstly, you have to change the decimal portion of 3.16 (0.16) into a fraction, then you simplify it by a common factor, which is 4. You then convert your whole number, which is 3, into an improper fraction by multiplying it by 25 and making that the numerator, 25 being the denominator of the fraction. Then, you add the two fractions and voila! You have a simplified fraction!
