when do we use BODMAS/PEMDAS

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by Anurag@Gurome » Thu Feb 23, 2012 7:15 pm
afnanmoh wrote:hello

i got confused..
when do we use BODMAS/PEMDAS?
BODMAS/PEMDAS is used when there are two or more than two operations in a single expression.

Example: 8 + 1 * 2 = (8 + 1) * 2 = 9 * 2 = 18
OR 8 + 1 * 2 = 8 + (1 * 2) = 8 + 2 = 10

In such cases, comes the importance of PEMDAS/ BODMAS rule.

PEMDAS stands for Parentheses, Exponents, Multiplication/Division, and Addition/Subtraction.

Hope that helps.
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by EugeneTownsend » Wed Sep 04, 2019 10:57 pm
They are basically the same

B - Brackets = P - Parentheses
O - Order = E - Exponents i.e. Powers
D - Division != M - Multiplication
M - Multiplication != D - Division
A - Addition = A - Addition
S - Subtraction = S - Subtraction
So we see the only difference is between the multiplication and division operators. Both are acronyms designed to be easy to remember but don't quite tell the full story. The central idea the two acronyms try to get across is that you should do multiplication and division before addition and subtraction.

Now there are some awkward cases like 6/2*3, 6*3/2 and 6/3/2. Neither rule works for all these case. The real rule is that when the operations are of the same precedence, (like * and / ) you do the operations from left to right. Hence 6/2*3 = (6/2) * 3 = 3 * 3 = 9 and 6 * 3 / 2 = (6 * 3) / 2 = 18 / 2 = 9 and 6/3/2 = (6/3)/2 = 2/2 = 1.

The same happens with + and -. So 6 - 2 - 3 = (6 - 2) - 3.

Also, check the PEMDAS calculator online