What is 0.999 rounded to one decimal place?

0.999 rounded to one decimal place is 1.0.

When rounding numbers, we look at the digit immediately after the place to which we are rounding. In this case, we are rounding to one decimal place, so we focus on the second decimal digit. The number 0.999 has the digits 9, 9, and 9. The first 9 is in the tenths place, the second 9 is in the hundredths place, and the third 9 is in the thousandths place.

To round to one decimal place, we look at the hundredths place, which is the second digit (another 9). According to rounding rules, if this digit is 5 or greater, we round up the digit in the tenths place by one. Since the hundredths place is 9, which is greater than 5, we round up the tenths place from 9 to 10. However, since 10 is not a single digit, it carries over, making the number 1.0.

This process ensures that 0.999, when rounded to one decimal place, becomes 1.0. This might seem surprising at first, but it follows the standard rules of rounding in mathematics. Understanding these rules is crucial for accurately rounding numbers in various mathematical contexts.