Rounding to the nearest tenth is a method of approximating a decimal number to the nearest tenth place value. The tenth place value is the first number that appears after the decimal point. To round a decimal number to the nearest tenth, we need to look to the right of the tenths place, which is the hundredths place. If the digit in the hundredths place is 5 or greater than 5, we need to add one to the digit in the tenths place. If it is 4 or less than 4, the tenths place digit remains the same. All the digits to the right of the tenths place should be changed to 0.

For example, to round 7.57 to the nearest tenth, we look at the digit in the hundredths place, which is 7. Since 7 is greater than 5, we add one to the digit in the tenths place, which is 5. Therefore, 7.57 rounded to the nearest tenth is 7.6.

In summary, rounding to the nearest tenth means approximating a decimal number to the nearest tenth place value by looking at the digit in the hundredths place and rounding the digit in the tenths place up or down accordingly.