Hints :
(a) Addition of digits of units place 5 + 8 = 13. Thus, we will mark one more sign on poorven digit of 6 and we will put 3 below the sum (at the place of unit).
(b) In the addition of tens place 6 + 6= 13 (where 6 = 7).
(c) Therefore, mark one more, sign on poorven digit of 6 i.e., 0.
(d) Write the remainder 3 at the place of addition (tens place).
(e) 0 = 1 shall be written of hundreds place.
(f) Thus, 65 + 68 = 133
