Multiplying and dividing in scientific notation (example) | Pre-Algebra | Khan Academy

Learn how to simplify a multiplication and division expression using scientific notation. The expression in this problem is (7 * 10^5) / ((2 * 10^-2)(2.5 * 10^9)).

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[awkwarddoggo]

I like hearing his voice. It’s something I’ll remember for the rest of my life

[celestetholenrosenlof]

A heads up for those doing the scientific notation practice that this video references:
"To write the answer correctly in scientific notation, the first number needs to be between 1 and 10. In this case, we need to move the decimal one position to the right without changing the value of our answer."
That's according to the practice, but it's not covered in this video. So make sure to write it accordingly and solve that additional step.

[CheeseArmy]

I'm about to graduate 8th grade and I've been using Khan academy's videos since 6th grade! They're always a great help and super easy to follow along.

[crxnvlmn]

2:38, it should be a digit equal or greater than 1 but less than 10. It cannot just less than or equal to 9 because 9.5 x 10^n will pass as scientific.

[YourResidentPersonWhoDoesStuff]

So helpful! I have a feeling every time I start physics for the day I'm going to end up at one of these videos!

[Richie_damian]

This is the most complicated thing ever no joke

[sausymanman]

How are they so good with writing with a cursor?

[chungusmoomoo]

I’m taking the shsat and the diagnostic from khans is tomorrow wish me luck

[csseth]

please use multiplication sign [ cross], because the dot [ . ] it creates the confusion between decimal and multiplication.

[monicaperez]

Can this problem be solved by putting it in a TI-30xs calculator?

[michellestephens]

As always....another great video. I have learned so much from you!!! :)

[deanodelaon]

pls try to explain the lessons deeper, İ did'nt understand a thing😨

[Shexie]

Khan you are a great teacher.. Could you do a video for (640, 000)(2, 700, 000) / (120, 000)? so the 640, 000 and 2, 700, 000 will be on top like in this video and the 2, 700, 000 will be at the bottom? can you help me understand this?

[lemmeplay]

...I have no idea what just happened ='D. ( Clicked on the video at random)

[etherealis]

1/3 x 10^-7 Divided by 1/(18 x 10^-7)^3. I Get 6 x 10^-28. What's wrong ?

[dweems]

When he jumps from fractions to decimals without explaining how he got there I get so discouraged. It's really frustrating when someone teaches you as if you already know all of the material. I wouldn't be here if I did *sigh

[_alphasierra]

Something is wrong with the "1 to 9" part, the number should be 1-10, and not 10 itself. So even if you have it is still not over 10 and you can leave it that way

[jenniannie]

I think you made a mistake. You changed -2 to -7, but yet kept the -2 in the final answer. Your 2 looks like a 7 to you! lol