Subtracting Two Digit Numbers
How to subtract two digit numbers (for example 67  45).
 Place one number above the other so the tens' place digits and ones' place digits
are lined up. Draw a line under the bottom number.
67
45
 Subtract the two digits in the ones' place column. (7  5 = 2).
67
45
2
 Subtract the digits in the tens' place column (6  4 = 2) and place the answer below
the line in the tens' place column.
67
45
22
 If the ones' place digit that is being subtracted is larger than the top ones'
place digit, decrease the top tens' place digit by one and increase the top ones'
place value by ten before subtracting.

