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**sologuitar****Member**- Registered: 2022-09-19
- Posts: 467

College Algebra

Section R.2

Write each number as a decimal.

A. 2.1 x 10^(4)

Answer: 21,000

To obtain the answer, I moved the decimal point 4 places to the right.

Why move the decimal point to the right?

B. 3.26 x 10^(-5)

Answer: 0.0000326

To obtain the answer, I moved the decimal point 5 places to the left.

Why move the decimal point to the left?

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**Bob****Administrator**- Registered: 2010-06-20
- Posts: 10,464

If you followed the other post on this you'll see we are just reversing those examples.

eg. 2.1 x 10^(4) = 2.1 x 10000 = 21000. The point has moved four places because that's what multiplying by 10000 does.

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Sometimes I deliberately make mistakes, just to test you! …………….Bob

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**sologuitar****Member**- Registered: 2022-09-19
- Posts: 467

I thought the decimal point moves the number of spaces indicated by the power of 10.

Yes? No?

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**Bob****Administrator**- Registered: 2010-06-20
- Posts: 10,464

The number of noughts after the 1, and the power of ten amount to the same thing.

And if the power of ten is negative a similar rule applies.

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Sometimes I deliberately make mistakes, just to test you! …………….Bob

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**sologuitar****Member**- Registered: 2022-09-19
- Posts: 467

Really? I didn't know this fact. Math is a great road of information.

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