How do you round 10.99557429 to one decimal place?

To round 10.99557429 to one decimal place, you look at the digit in the tenths place, which is the second digit after the decimal point. In this case, the digit in the tenths place is 9. Since 9 is greater than or equal to 5, you round up the digit in the tenths place to the next higher number. Therefore, rounding 10.99557429 to one decimal place gives you 11.0.