Which place value is used to decide whether to round 245.2678 to the nearest thousandth?

To determine how to round the number 245.2678 to the nearest thousandth, the key is to identify the digit in the thousandths place, which is the third digit to the right of the decimal point. In this case, the digit in the thousandth position is 7, making the number 245.2678.

To round to the nearest thousandth, you also have to look at the digit immediately to the right of the thousandths place, which is in the ten-thousandths position. In 245.2678, this digit is 8. According to standard rounding rules, if this digit is 5 or greater, you would round up the digit in the thousandths place by one. Since 8 is greater than 5, you round the 7 up to 8.

Therefore, the place value that allows for the rounding decision is the ten-thousandth place, as it directly influences the rounding of the thousandth place. As such, identifying the relevant digits and their corresponding place values is crucial for accurate rounding.