If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

## Algebra basics

### Course: Algebra basics>Unit 1

Lesson 5: Order of operations

# Order of operations example

Simplify this tricky expression using the order of operations.   Expression include negative numbers and exponents. Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

• How Would one do 10 to the hundredth power?
• If n is any whole number, then 10^n is a 1 followed by n zeros.
So 10^100 is a 1 followed by a hundred zeros. This number is called a googol.

Have a blessed, wonderful day!
• So is 5 to the 2nd power 25?
• yes. if you square (A.K.A to the power of 2) a number, you multiply the number by itself twice.
• why do you multiply 2x(3+2) I don't see a times symbol
• Putting a number next to parenthesis, like 2x next to (3+2), counts as multiplication. The parenthesis is technically the multiplication question.

Example

3(5+ 7)

3(12)
=36
• How would you solve -(2)squared minus -54
• Exponents come before subtraction.
-(2)^2 - (-54) = -4 -(-54)
Next, clean up the signs on the 54 to get: -4 + 54

Hope this helps.
• I didn't understand that can you make another video explaining better.Plz
• Order of Operations is often called PEMDAS. This helps you remember which parts of a math problem to do first. It works like this:

5 + 2 / ((8-7)x2) x (5 x 2)
You do anything inside the parentheses first. That's the P in PEMDAS. If you have parenthese INSIDE a set of parentheses, you do the inner set first.
5 + 2 / (1 x 2) x (5 x 2) We solved the inner (8-7) first. 8 - 7 is 1.
5 + 2 / 2 x (5 x 2) When you have more that one operation to do at a step, you work left to right. So we solved (1 x 2) before we solve (5 x 2).
5 + 2 / 2 x 10
We don't have any exponents in this problem so we skip the E in PEMDAS.
5 + 1 x 10 Now we've reached the MD part of PEMDAS. We do all the multiplication AND division, starting at the left and working to the right. So we solve 2 / 2 first.
5 + 10 Still working on the MD part, solving the multiplication problem 1 x 10
15 The last part of PEMDAS is the AS step. We do all of the addition AND subtraction, starting at the left and working to the right.
• Wait so if we need to multiply a negative number with positive, it'll be a negative number?
• Yes. Ex: If someone owes you \$5, they have \$-5. If you decide that they need to pay you back double, they now owe you \$10. This means that they have \$-10. (The math is: -5*2=-10.)
• What is the property that says (-28)-(-2) is just like 28 + 2 but then you put a negative sign on the answer and to say something else i misspell "sign" as "sing" a lot.
• Why do we have to do so much just to solve this problem?
• If you don't do PEMDAS, you may get a different answer (this only applies for some questions). It is just "safer" to try and do PEMDAS or PEDMAS or (you get the idea) in problems with multiple operations. Just saying, this is what I got out of your question. I may have got the wording wrong but I hope this helps anyway!