Place value does not only concern digits found before the decimal point, there are also values place on digits appearing after the decimal point.
Example: 123.456
1 is in the hundreds value; 2 is in the tens value; 3 is in the ones value. 123 are found before the decimal point. 456 follows after the decimal point. After the decimal point the value will begin at tenths.
4 is in the tenths value; 5 is in the hundredths value, 6 is in the thousandths value.
To write the decimals of the above fractions and round them to the thousandths place, we must look on the place value after the decimal point.
4/5 = 4 ÷ 5 = 0.800
1/5 = 1 ÷ 5 = 0.200
3/8 = 3 ÷ 8 = 0.375