Addition and subtraction using the column method

​​In a nutshell

While adding and subtracting numbers with a calculator is indeed very fast and easy, it is still important to know how to add and subtract numbers by hand.

Addition using the column method

To add two or more numbers using the column method, use the following procedure. 

procedure

1. ​Write the numbers in a column, making sure that the place values are aligned. Draw a line underneath the lowest number.
   
2. Starting with the rightmost digit, add the numbers in that place value column. If the numbers add up to $$9$$​ or less, then write it down on the correct column beneath the line. If the numbers add up to $$10$$​ or more, only write down the unit digit beneath the line. Write the other digit(s) above the next column.
3. Move onto the next column to the left and repeat, remembering to add any newly added digits that came from the previous column's addition.
   
4. Repeat this procedure until the last column has been added. If the last column adds up to more than $$9$$​, then it's fine to write down the whole number.

Example 1

What is $$358+294$$?

​$$\underline{358+294=652}$$​​

​

Subtraction using the column method

Subtracting two numbers using the column method is very similar to addition.

procedure

1. ​Write the numbers in a column, making sure that the place values are aligned. Draw a line underneath the lowest number.
   
2. Start from the rightmost digit. If the top number is bigger than the bottom number, then subtract as normal. If the top number is smaller than the bottom number, then "borrow" a $$1$$ from the number to the left and "give" it to the top number - making it a two digit number. Perform the subtraction as usual.
3. Move onto the column to the left and repeat the above step, making sure to remember that the number on the top is $$1$$ less than it used to be due to the "borrowing".
   
4. Repeat until the last column has been subtracted.
   

Example 2

What is $$358-294$$?

​$$\underline{358-294=64}$$​​

​​