The number ones place has a value from 0 to 9, the number on tens place has a value from 10 to 90, the number on hundreds place has a value from 100 to 900, and so on.
For the number on the RHS, the number on the one's place is 2 and the number on the tens place is 7. Adding these two numbers gives
[tex]7+\text{ 2 = 9 }[/tex]Hence, the sum is 9.
