# Video: Writing Quantities in Scientific Notation

An estimate for the height of Mount Everest is 30000 feet. Write this number in scientific notation.

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### Video Transcript

An estimate for the height of Mount Everest is 30000 feet. Write this number in scientific notation.

Scientific notation is used to represent very large or very small numbers. Scientific notation will be in the form of a number times 10 to some number that’s the power. Now this number needs to be greater than or equal to one, but less than 10. So it can be a one. It can be larger than one. But it needs to be less than 10.

And the way we find that number is to take whatever number we’re converting and move its decimal point, so that way it is between one and 10. So 30000 could be written as 30000.0. Now to make 30000 be smaller, we have to move the decimal point to the left.

If we have to move the decimal point to the left, the exponent will be positive. If we will have to move the decimal point to the right, the exponent would be negative. So again, we’re moving it to the left. So our number for the exponent will be positive.

So let’s count how many times we have to move our decimal point so that way the number is between one and 10, where it could actually be equal to one. But it needs to be less than 10. One, two. If we would stop here, we would be at three hundreds. That’s still not enough. So let’s keep going. Three and then finally at four, we’re at 3.00000, which is the same thing as 3.0.

So our number is 3.0. And our scientific notation tells us that we need to put times 10 to the positive four power because we moved the decimal place to the left. So the exponent should be positive. And we moved it four times. So we have 3.0 times 10 to the fourth power.

This would be in scientific notation. And we also could just have three times 10 to the fourth power. We wouldn’t have to put 3.0 unless we would like to. So either of these answers would work. We could pick one.