What is 0.123 rounded to one decimal place?

0.123 rounded to one decimal place is 0.1.

When rounding a number to one decimal place, you look at the second digit after the decimal point. In this case, the number is 0.123. The first digit after the decimal point is 1, and the second digit is 2. According to rounding rules, if the second digit is less than 5, you round down. If it is 5 or more, you round up.

Here, the second digit is 2, which is less than 5. Therefore, you round down, keeping the first digit after the decimal point as it is. This means 0.123 becomes 0.1 when rounded to one decimal place.

Rounding is a useful skill in mathematics and everyday life. It helps to simplify numbers, making them easier to work with, especially when precision is not crucial. For example, when dealing with money, measurements, or statistics, rounding can make calculations quicker and results easier to understand. Remember, the key is to look at the digit immediately after the place to which you are rounding to decide whether to round up or down.