Everest - Tuesday
Maths - Order of Operations
In this video from, the order of operations is used to solve a long calculation.
When you work out a calculation with more than one operation (eg 8 + 2 × 3) follow the BIDMAS rule. Without this rule you could get different answers - so getting the order of operation correct is important.
The BIDMAS rule
BIDMAS stands for Brackets, Indices, Division and Multiplication, Addition and Subtraction.
So the order you should do your calculations in is:
- Division and Multiplication (start on the left and work them out in the order that you find them)
- Addition and Subtraction (when only addition and subtraction are left in the calculation, work them out in the order you find them - starting from the left of the calculation and working towards the right)
All of these terms are fairly obvious except for 'Indices' - which are just powers (eg 2³ or 4²). 'Indices' are also known as 'orders'. So you might also know this rule as BODMAS (Brackets, Orders, Division and Multiplication, Addition and Subtraction).
What is 4 + 2 x 3?
If you calculate the 4 + 2 part first you get:
4 + 2 x 3 = 6 x 3 = 18
If you calculate the 2 x 3 part first you get:
4 + 2 x 3 = 4 + 6 = 10
These are two very different answers, but only one is correct.
In BIDMAS, multiplication comes before addition, so multiply 2 by 3 first:
4 + 2 x 3 = 4 + 6 = 10, so this is the right answer.
What is 9 - 4 + 3?
This calculation has only addition and subtraction. So work them out from left to right:
9 - 4 + 3 = 5 + 3 = 8
Notice that if you didn't go from left to right you would get a different answer:
9 - 4 + 3 = 9 - 7 = 2
That would be incorrect, which is why we work them out from left to right.
Once you know the other of the operations, working out these problems should be easy. Pause the video when asked and try the questions.
Please click here for your worksheet.
English - Commas, brackets and dashes
Watch the video below to remind you about commas, brackets and dashes.
Brackets, dashes and commas indicate parentheses (parentheses is the plural of parenthesis).
Parenthesis is a word or clause inserted into a text as an afterthought (or as extra information).
A pair of brackets, commas or dashes can be used to enclose the extra information or afterthought.
Commas: ‘The lion, who has sharp teeth, ate his dinner.’ (Commas are used here as the parenthesis is important to the sentence)
Brackets: ‘The lion (with a fluffy mane) ate his dinner.’ (Brackets are used here as the parenthesis isn’t vital to the sentence)
Dashes: ‘The lion - who wasn’t very cool – ate his dinner.’ (Dashes are used here as the parenthesis is informal)
Watch this video to remind yourself of how commas can be used to make your sentences clear and easy to understand.
Commas for clarity
Adding a comma can change the meaning of a sentence.
Let's eat Callum - We're going to eat Callum.
Let's eat, Callum - We're eating with Callum.
Commas to add extra information
In longer sentences, you can use commas to separate out extra information (parenthesis) and make the sentence easier to read.
Commas and clauses
A clause is the building block for a sentence. Commas can be used to break up sentences that have more than one clause and make them easier to read.
When Albert saw the food, his tummy started to rumble.
Albert got used to the blue spots, but then they started itching.
Both these sentences have a subordinate clause. Subordinate clauses do not make sense on their own because they need the main part of the sentence to make sense, so they are connected with a comma.
When you don’t need a comma
If the clauses make sense on their own, you don’t need to use a comma. For example:
Albert was excited about eating. He wanted to use a knife and fork.
Open the worksheet here and do the task on page 4 of the document.