When rounding ampacity values, to what should the value of 20.45 be rounded?

When rounding numbers, the standard method is to look at the digit immediately following the place you are rounding to determine how to round. In this case, we want to round the value 20.45 to the nearest whole number, which involves focusing on the digit in the tenths place.

The value 20.45 has a whole number part of 20 and a decimal part of .45. Since we are rounding to the nearest whole number, we look at the 4 in the tenths place. According to rounding rules, if this digit (the tenths digit) is less than 5, we round down, and if it is 5 or greater, we round up.

Here, because the tenths digit (4) is less than 5, we round down the 20.45 to 20 A. Therefore, rounding 20.45 results in a value of 20 A. This is why the answer is correct.