Order of Operations and PEMDAS

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Basic Math › Order of Operations and PEMDAS

Questions 1 - 9
1

Solve:

Explanation

Use the order of operations: PEMDAS (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction).

We want to solve what's in the parentheses first.

Now, do the division and the multiplication.

Therefore our equation becomes:

Finally, subtract.

2

Simplify

Explanation

We start with what is inside the parentheses, so becomes .

Next, we take care of any exponents, giving us .

Next, we take care of multiplication/division, giving us or .

Finally, we carry out our addition/subtraction, leaving us with .

3

Solve:

Explanation

Use order of operations, PEMDAS (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction) to solve.

Since there are no parentheses or exponents we can go straight to multiplication and division.

and

Therefore the following happens:

Then add and subtract.

4

Explanation

This is a classic order of operations question, and if you are not careful, you can end up with the wrong answer!

Remember, the order of operations says that you have to go in the following order of operations: Parentheses, Exponents, Multiplication, Division, Addition, Subtraction (also known as PEMDAS). In this equation, you will start with the parentheses. In the parentheses, we have

.

But within the parentheses, you still need to follow PEMDAS. First, we will solve the exponent, and the square of 2 is 4. Then, we'll divide 16 by 4, which gives us 4, so we can rewrite our original equation as

.

We can now divide into , which gives us

.

The last step is to add and subtract the numbers above, paying careful attention to negative signs. In the end, we end up with because added to equals , and minus equals .

5

Solve:

Explanation

Using PEMDAS, we do the parenthetical bit first:

Now, we do multiplication and division:

Finally, subtract.

6

When evaluating the expression

,

in which order must you work the three operations?

Cubing, multiplication, subtraction

Cubing, subtraction, multiplication

Multiplication, cubing, subtraction

Subtraction, multiplication, cubing

Subtraction, cubing, multiplication

Explanation

By the order of operations, in the absence of grouping symbols, the exponent (represented here by cubing) must be worked first. The multiplication must be worked second, followed by the subtraction.

7

When evaluating the expression

,

which of the five operations must be carried out third?

Squaring

Division

Multiplication

Addition

Subtraction

Explanation

By the order of operations, any operations within parentheses must be carried out first; there are two here, the addition and the subtraction. After this is done, the exponent, or squaring, must be worked before the other operations. Squaring, the third operation, is therefore the correct answer.

8

When evaluating the expression

,

in which order must you work the three operations?

Multiplication, subtraction, addition

Multiplication, addition, subtraction

Subtraction, multiplication, addition

Subtraction, addition, multiplication

Addition, subtraction, multiplication

Explanation

By the order of operations, in the absence of grouping symbols, multplication must be worked before adding or subtracting. Then the addition and subtraction must be worked in left-to-right order; the subtraction is at left, so the subtraction is worked next, followed by the addition.

9

Explanation

Using order of operations, we need to solve whatever is in the parentheses first.

Next, do the multiplication and division.

Finally, add and subtract.

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