The 'tenth' place is the number 4.
First, look at the number to the right.
If the number is 5 or less, just take away all the digits to the right of 4 in this case.
If the number is more than 5, add 1 to 4 which gives 5, then take away all the digits to the right of 5 in this case.
639.497 9 is more than 5 so add 1 to 4 and take away the digits to the right.
639.5
First, look at the number to the right.
If the number is 5 or less, just take away all the digits to the right of 4 in this case.
If the number is more than 5, add 1 to 4 which gives 5, then take away all the digits to the right of 5 in this case.
639.497 9 is more than 5 so add 1 to 4 and take away the digits to the right.
639.5