How to subtract integer numbers: calculate the difference and learn to subtract multiple digits numbers, column subtracting method, from right to left

Let's learn by an example.
Subtract the numbers:
2,043 - 1,959

Method used below: column subtracting, from right to left (traditional)


Stack the numbers on top of each other.

The ones digits line up in the first column from the right.

The tens digits line up in the next column to the left.

And so on...


 2043
- 1959

?

Subtract column by column; start from the column on the right

Subtract the digits in the ones column:

3 - 9 = ?

The second digit is larger than the first.
Borrow from the next column to the left.

The borrowing is a two step process:


Subtract 1 from the top digit in the column of the tens: 4 - 1 = 3.
Cross out the top digit you've borrowed 1 from: 4.
Write the answer above that digit: 3.


When borrowing, 1 ten = 10 ones.
Add 10 to the top digit in the column of the ones: 10 + 3 = 13.


   3 
 20413
- 1959

     

After borrowing, the subtraction has become:
13 - 9 = 4.
4 is the ones digit.
Write it down at the base of the ones column.


   3 
 20413
- 1959

    4

Subtract the digits in the tens column:

4 3 - 5 = ?

The second digit is larger than the first.
Borrow from the next column to the left.

Subtract 1 from the top digit in the column directly to the left.
But that digit is zero. You need to go further left.


Subtract 1 from the nearest column to the left with a non-zero top digit.
That is the column of the thousands: 2 - 1 = 1.
Cross out the top digit you've borrowed 1 from: 2.
Write the answer above that digit: 1.


Cross out the zero(s) that you were going across to the left: 0.
Write a 9 above each one of the crossed out zeros.
Why? In fact we have subtracted 1 from 20: 20 - 1 = 19.


When borrowing, 1 hundred = 10 tens.
Add 10 to the top digit in the column of the tens: 10 + 3 = 13.


 1913 
 20413
- 1959

    4

After borrowing, the subtraction has become:
13 - 5 = 8.
8 is the tens digit.
Write it down at the base of the tens column.


 1913 
 20413
- 1959

   84

Subtract the digits in the hundreds column:

0 9 - 9 = 0.
0 is the hundreds digit.
Write it down at the base of the hundreds column.


 1913 
 20413
- 1959

  084

Subtract the digits in the thousands column:

2 1 - 1 = 0.
0 is the thousands digit.
Write it down at the base of the thousands column.


 1913 
 20413
- 1959

 0084

Leading zeros

When leading zeros occupy the most significant digits of a natural number, they could be left blank and the numeric value stays the same:

0084 = 84

Final answer: