It is already rounded to the nearest 'hundredth' ( NOT hundered).
The colum names for 6.78 are ;-
'6' ; units
Decimal point
'7' ; Tenths
'8' ; Hundredths
Note the '----ths' suffix on the decimal column name.
Next column would be 'thousandths'.
678 is rounded nearest hundred is 700
6,100
800
The answer is 500,000
700
678
700
690
300
438 rounded to nearest hundered
678 500 000
nearst hundered is 3800