What is 8.4 rounded to the nearest whole number?

When rounding a decimal number to the nearest whole number, you look at the first decimal place. If it is 5 or greater, you round up; if it is less than 5, you round down. In this case, 8.4 has a tenths place value of 4, which is less than 5. Therefore, when rounded to the nearest whole number, 8.4 becomes 8.