To correct the number 9.999957 to four decimal places, we round it to 9.99996.

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Here are 5 related questions:

1. How do you round the number 3.141592 to three decimal places?
2. What is the rule for rounding numbers to a specific decimal place?
3. How do you round 0.9995 to two decimal places?
4. What is the difference between rounding up and rounding down?
5. How do you round 123.45678 to the nearest integer?

Tip: When rounding a number, if the digit immediately after the desired decimal place is 5 or greater, you round up the last digit.