Transcript Document

BODMAS
Why do we need BODMAS ?
when you see something like...
7 + (6 × 52 + 3)
... what part should you calculate first?
Start at the left and go to the right?
Or go from right to left?
Calculate them in the wrong order, and you will get a
wrong answer !
So, long ago people agreed to always follow certain rules
when doing calculations. One of them is “BODMAS”
What is BODMAS ?
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Bracket = ( )
Orders or power Of = Powers and Square Roots, etc.
Multiplication = ×
Division = ÷
Addition = +
Subtraction = Other names for BODMAS = "Exponents" is used in
Canada, and so you might prefer "BEDMAS". There is
also "Indices" so that makes it "BIDMAS". In the US they
say "Parenthesis" instead of Brackets, so they say
"PEMDAS“.
How do I Remember ? BODMAS!
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B Brackets first
O Orders (i.e. Powers and Square Roots, etc.)
DM Division and Multiplication (left-to-right)
AS Addition and Subtraction (left-to-right)
Brackets
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Brackets are Parenthesis ( ).
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Brackets are used to group things.
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This is the first thing you do in a question.
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Do things in Brackets First.
 6 × (5 + 3) = 6 × 8 = 48
 6 × (5 + 3) = 30 + 3 = 33 (wrong)
Order or Exponents
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(Powers, Roots) before Multiply, Divide, Add or Subtract.
Example
Exponents are used to shorten the equation.
If you see an exponent, you multiply the main number
by itself that many times.
Solve the Exponents first
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5 × 22 = 5 × 4 = 20
5 × 22 = 102 = 100 (wrong)
Multiplication
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In the Order of Operations, you would complete the
equation left to right, doing which ever one appears first,
Multiplication or Division.
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The symbol for multiplication is ‘x’.
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Remember to go from left to right.
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Multiply or Divide before you Add or Subtract.
 2 + 5 × 3 = 2 + 15 = 17
 2 + 5 × 3 = 7 × 3 = 21 (wrong)
Division
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In the Order of Operations, you would complete the
equation left to right, doing which ever one appears first,
Multiplication or Division.
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Division is an equation that puts numbers in to groups.
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The Division symbol is ÷
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Remember to go from left to right
 30 ÷ 5 × 3 = 6 × 3 = 18
 30 ÷ 5 × 3 = 30 ÷ 15 = 2(wrong)
Addition
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In the Order of Operations, you would complete the
equation left to right, doing which ever one appears first,
Addition or Subtraction.
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Addition is adding numbers together.
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The symbol for addition is +.
Example: 6 + 9 = 15
Subtraction
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In the Order of Operations, you would complete the
equation left to right, doing which ever one appears first,
Addition or Subtraction.
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Subtraction is taking away a specific number.
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The symbol for subtraction is -.
Example: 17 – 8 = 9
Summary
BODMAS is a word which helps us to remember the order
we do operations in a maths sum.
It stands for brackets first, then powers of .
Next do division or multiplication (it does not matter which
way round you do these).
Finally do addition or subtraction (again, it does not matter
which way you do these.)
Some people use the word Bidmas. In this case powers of is
replaced by indices , which means the same thing.
Copy and fill in the gaps using the words below
operations
multiplication
subtraction
division
brackets
powers of
addition
Sample Equation
4 × 3 + 6 - (12 ÷ 22 + 5)
= 4 × 3 + 6 - (12 ÷ 4 + 5)
= 4 × 3 + 6 - (3 + 5)
= 4 × 3 + 6 - (8)
= 12 + 6 – 8
= 10