well I would write this as a fraction. :D
.1 is equal to 1/10 and .1and .10 is equal to 10/100
so the amount of zeros on the bottom = the amount of numbers past the decimal point.
so you would have
[tex]6 \frac{371}{1000}[/tex]
then you multiply the whole number by the denominator, and add it to the numerator
[tex]6*1000=6000[/tex]
[tex]6000+371=6371[/tex]
now you put that number over the original denominator.
[tex]\frac{6731}{1000}[/tex]