When to use bidmas or bodmas?

Answer 1

If the problem includes more than just one order of operation, then bidmas or bodmas (or whatever you have been taught to remember what it is) applies. What are the different orders of operations?

1. Parentheses or brackets (P or B)

2. Exponents, orders. indices (E, O, or I)

3. Multiplication/division (M and D)

4. Addition/subtraction (A and S)

If you have a problem consisting of operations from two different orders (say a parenthesis and multiplication, or an exponent and addition), then you do the highest order operation first. The only time it is okay to not use order of operations is if every operation in the problem is of the same order. In that case, you can work from left to right.

Example: 5+5+5-5+5+5-5+5X0

This has operations of two different orders. Therefore BIDMAS applies. Of the two operations, multiplication is of the highest order and must be done first.

5+5+5-5+5+5-5+5x0

=5+5+5-5+5+5-5+0

Now that all the operations are of the same order, we can work left to right.

=10+5-5+5+5-5+0

=15-5+5+5-5+0

=10+5+5-5+0

=15+5-5+0

=20-5+0

=15+0

=15

If, on the other hand, we have problems like this:

5+5+5-5+5+5+5-5+5

or

5x5x5x5x5x5x5

then we can work from left to right since all the operations in both problems are of the same order.