Adding Two-Digit Numbers with Paper and Pencil

How to add two two-digit numbers (for example 45 + 67) with paper and pencil.

  • Write one number above the other so that the tens' place digits and ones' place digits are lined up. Draw a line under the bottom number.
  • 45
    67
    
  • Add the ones' place digits. (5 + 7 = 12). This sum is a two-digit number so place a one above the tens' place column and place the two below the line in the ones' place column.
  • 1
    45
    67
     2
    
  • Add the numbers in the tens' place column (1 + 4 + 6 = 11) and place the answer below the line and to the left of the ones' place sum.
  •  1
     45
     67
    112






Find the Sum of the two Numbers.

  +     =