Math CentralQuandaries & Queries


Question from Emily, a student:

For my Math homework, my pre-algebra2, I have to write the Exponential Form of 125 x 25 and 81x 27. How should I write those in the exponential form???


Hi Emily.

Exponential form is, as you probably guessed, a form that shows exponents.

Let me give you a sample so you can try those two questions yourself.

Write in exponential form: 128 x 32.

First I have to decide if each of these numbers is a power of another number. I know 4 x 4 is 16 and 16 x 2  is 32. So 32 = 2 x 2 x 2 x 2 x 2  = 25. Also I know that 128 is 32 x 4, so 128 is 25 x 2 x 2 = 27. Thus,

128 x 32 = 25 x 27.

The last step is to realize that if two factors have the same base (in this case, both bases are 2), then you can add the exponents:

25 x 27 = 25+7= 212.

And that is in exponential form. So the final answer is

128 x 32 = 212.

Now you try the same idea with your questions.

Stephen La Rocque

About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS