7/9 expressed as a decimal is 0.77777.... which is a recurring decimal value. i.e. it has the same decimal value and continues to infinity.
You can determine this decimal value by dividing 7 by 9.
The rule to round up decimal number is the following:
• If the next decimal digit is between 0 and 4, you leave the value as it is.
,
• If the next decimal digit is between 5 and 9, you have to round the value one up.
To round 0.77777 to the next hundredth (second place after the decimal dot), you have to look at the decimal digit in the thousands place (third place after the decimal dot)
0.777 → the third decimal digit is between 5 and 9, so you have to round the second decimal digit one up, i.e. from 7 to 8.
The value rounded to the nearest hundredth is then 0.78
Option B is correct.