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Written Methods for Subtracting Large Numbers

Maths: Year 3 & 4 National Curriculum, topic 5.2.2

Subtracting Numbers with More than 4 Digits

When subtracting larger numbers, you use written methods to show your workings. You should use the column method for subtracting. You use the column method slightly differently when subtracting.

Column method

Column method

  • Line up the place value in the two numbers you are trying to subtract.
  • I'm trying to do 7,401 − 3,111 here.
Start at the 'ones'

Start at the 'ones'

  • Start by subtracting from the 'ones' column.
  • The 'ones' column has the calculation 2 − 1 = 1.
Next, you subtract the 'tens'

Next, you subtract the 'tens'

  • Next, you move to the 'tens' column.
  • The 'tens' column has the calculation 0 − 1.
  • You cannot write the answer to 0 − 1 in the column.
  • You need to use 'borrowing' to find your answer.
Borrowing

Borrowing

  • 'Borrowing' is when you borrow 1 from the next biggest column.
  • In this example, you need to borrow 1 'hundred' from 4 'hundreds'.
  • Borrowing 1 'hundred' from 4 'hundreds' leaves you with 3 'hundreds' and 10 'tens'.
After you've 'borrowed'

After you've 'borrowed'

  • Now you can complete the subtraction in the 'tens' column.
  • The 'tens' column now has the calculation 10 − 1 = 9.
Now subtract the 'hundreds'

Now subtract the 'hundreds'

  • Next, subtract from the 'hundreds' column.
  • The 'hundreds' column has the calculation 3 − 1 = 2.
  • The calculation in the 'hundreds' column is 3 − 1 and NOT 4 − 1.
Lastly, subtract the 'thousands'

Lastly, subtract the 'thousands'

  • Finally, subtract from the 'thousands' column.
  • The 'thousands' column has the calculation 7 − 3 = 4.

Test yourself on Written Methods for Subtracting Large Numbers

  • What number goes into the 'hundreds' column in this calculation?

  • What number goes into the 'tens' column in this calculation?

  • What number goes into the 'tens' column in this calculation?

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