To round 845.001 to the nearest thousandth, follow these steps:
Identify the thousandth place: In the number 845.001, the thousandth place is the third digit after the decimal point, which is 0.
Look at the ten-thousandth place: The digit in the ten-thousandth place (the fourth digit after the decimal point) is 9.
Apply rounding rules: Since the digit in the ten-thousandth place (9) is greater than or equal to 5, you round the thousandth place up by 1.
Final rounded result: The thousandth place (0) becomes 1, so the number rounds to 845.001
Thus, 845.001 rounded to the nearest thousandth is 845.001