To round the number 78.931 to 2 decimal places, follow these steps:
1. Identify the digit in the third decimal place of the number. In this case, the number is 78.931, and the digit in the third decimal place is 1.
2. Determine whether the digit in the third decimal place is less than 5 or greater than or equal to 5. If it is less than 5, you will round down, and if it is 5 or greater, you will round up. Here, the digit is 1, which is less than 5.
3. Since the digit in the third decimal place (1) is less than 5, you keep the second decimal place digit as it is and remove everything after it.
Therefore, when rounding 78.931 to 2 decimal places, we get the answer:
78.93
