Subtraction Calculations

There are many different ways to subtract numbers from one another. It is important to choose a method that works quickly and easily for you. For subtracting two whole numbers, you may choose to do the sum in your head.

If you want to write it down, you can choose to use a number line. You start with the number that is being taken away and count upwards to the original number

Example 1:

Let’s say the question you’ve been given is  83 –  37 =?

This is how we would set up the number line:

We then could add up the differences

3 + 40 + 3 = 46

We can check this is the right answer by adding 46 and 37

37 + 46 = 83     so we know that 46 is definitely the right answer.

If you don’t want to use a number line, especially on larger numbers, it may be easier for you to use the column method for subtraction. Like in the addition method, we have to first line up the digits in the correct place value then begin the subtraction in the units column. However, if we don’t have a larger number on the top of the column, we have to borrow from the next column.

Example 2:

Let’s say that the question we’ve been given is  925 – 264 =?

his is how we would do the sum:

These methods would also work with decimal numbers but if you find decimals difficult, it might be easier for you to treat them as whole numbers during the calculation.

Example 3:

Let’s say that the question you’ve been given is 0.6 – 0.43 =?

First let’s rewrite this as 0.60 – 0.43. Once we’ve done this, all we need to do is find the answer to

60 – 43 which is 17. We have to turn this back into a decimal so the answer would be 0.17.

0.6 – 0.43 = 0.17

Alternatively, let’s have a look how this would look in column method form .