Topic Five (1.5): Order of Operations

Introduction Icon.png Introduction

There is an agreed order of operations (like add or subtract) in Maths. If we don't follow this order there can be multiple answers for a calculation with several operations in it.  First, we work out any brackets and apply indices (powers like 22, then we divide and multiply followed by adding and subtracting. The textbook calls this method BIDMAS to help us remember - Brackets, Indices, Divide or Multiply, then Add or Subtract (working from left to right in the question).

You may see ‘order’ being used for power instead of ‘indices’, which makes the Mnemonic BODMAS, or ‘parentheses’ being used instead of ‘brackets’ and ‘exponents’ instead of ‘indices’, in the Mnemonic PEMDAS.

Consolidate Icon.png Warm Up 

First complete the skill checker on page 92.

If you need a refresher look back to last lesson’s work!

Interact Icon.png Working through the coursebook

  • You may enjoy singing along to this song, which will help you remember the Mnemonic PEMDAS:

  • For a full explanation of its application, watch: (Please note, this tutor uses O for order rather than I for indices. Both mean "power", so the method is the same)

  • Read and make notes of the worked example on pages 93-94, if you think it will help you.
  • Remember  - we add or subtract in the order they appear in the question!

Therefore, 10 – 4 + 3 = 6 + 3 = 9.

  • Now see if you can answer the Band 2 questions on pages 95-96.
  • If you would like more practice, then work through these lessons on the MyMaths website:

EXPLORE – Order of operations and brackets (MyMaths) Links to an external site.

  • You may also want to watch the following Math Antics video:

Optional Activities Icon.png Plenary

This pairs game will test your short-term memory skills, as well as your BIDMAS ones!

PLAY - Order of operations: Pairs game (MyMaths) (slide 4 only) Links to an external site.

Bridge Icon.png Support activities for this topic

The Band 1 questions on page 95 will help build your skills on this topic.

Stretch Icon.png Extension activities for this topic

If you would like more of a challenge on this topic, go to page 96 and attempt the Band 3 questions.