Final answer:
The correct expression for the number four hundred and seventy-three thousandths is '3 x (1/1000)', which is option 'd'.
Step-by-step explanation:
The expression that shows the value of the digits in the number four hundred and seventy-three thousandths is 3 x (1/1000). This is because the digit 3 is in the thousandths place, which means it is three thousandths or 3/1000. So, the correct answer is option 'd', 3 x (1/1000).