Round 1.5 to one decimal place

If the last digit in 1.50 is less than 5, then remove the last digit.

If the last digit in 1.50 is 5 or more and the second to the last digit in 1.50 is less than 9, then remove the last digit and add 1 to the second to the last digit.

If the last digit in 1.50 is 5 or more and the second to the last digit in 1.50 is 9, then remove the last digit, make the second to last digit 0, and add 1 to the number to the left of the decimal place.

When rounding 1.50 to one decimal place we use One Decimal Place Rule #1. Therefore, the answer to "What is 1.50 rounded to 1 decimal place?" is:

1.5