Exponents

The exponent of a number says how many times to use the number in a multiplication.

8 to the Power 2

In 8two the "2" says to use 8 twice in a multiplication,
so eight2 = 8 × 8 = 64

In words: 82 could be chosen "eight to the power ii" or "8 to the 2nd power", or simply "8 squared"

Exponents are also called Powers or Indices.

Some more than examples:

Example: 53 = five × 5 × v = 125

  • In words: 5three could be called "5 to the third power", "five to the power iii" or simply "5 cubed"

Example: 2iv = 2 × 2 × 2 × 2 = xvi

  • In words: iiiv could be called "2 to the fourth power" or "2 to the power 4" or merely "two to the quaternary"

Exponents brand it easier to write and employ many multiplications

Example: 9half dozen is easier to write and read than ix × 9 × 9 × 9 × nine × 9

Yous can multiply whatsoever number past itself as many times as you desire using exponents.

Endeavor hither:

algebra/images/exponent-calc.js

And so in full general:

an tells you to multiply a by itself,
so at that place are north of those a'southward:
exponent definition

Another Way of Writing Information technology

Sometimes people use the ^ symbol (above the half-dozen on your keyboard), as it is easy to type.

Example: 2^4 is the same every bit 2four

  • ii^4 = 2 × 2 × 2 × 2 = xvi

Negative Exponents

Negative? What could be the opposite of multiplying? Dividing!

And then nosotros divide by the number each time, which is the same as multiplying by one number

Example: viii-1 = 1 8 = 0.125

We can go along on like this:

Example: 5-3 = 1 v × i 5 × 1 five = 0.008

But it is often easier to do it this style:

5-3 could also be calculated like:

1 v × 5 × five = 1 v3 = 1 125 = 0.008

Negative? Flip the Positive!

negative-exponent

That last instance showed an easier manner to handle negative exponents:

  • Calculate the positive exponent (anorth )
  • Then take the Reciprocal (i.east. 1/an )

More Examples:

Negative Exponent Reciprocal of
Positive Exponent
Answer
4-ii = 1 / 42 = ane/16 = 0.0625
10-3 = 1 / 103 = 1/1,000 = 0.001
(-2)-three = 1 / (-2)three = 1/(-8) = -0.125

What if the Exponent is 1, or 0?

ane If the exponent is 1, and then you lot only accept the number itself (example 9i = 9)
0 If the exponent is 0, then y'all go 1 (example ix0 = one)
But what nigh 00 ? It could be either 1 or 0, and so people say it is "indeterminate".

Information technology All Makes Sense

If you look at that table, you will see that positive, zero or negative exponents are really part of the same (fairly simple) pattern:

Case: Powers of v
.. etc.. exponent 5 times larger or smaller
52 five × v 25
51 5 5
50 i 1
5-1 1 5 0.2
5-2 i 5 × ane five 0.04
.. etc..

Be Careful About Grouping

To avoid confusion, use parentheses () in cases like this:

With () : (−2)2 = (−ii) × (−2) = 4
Without () : −iiii = −(22) = −(2 × ii) = −4

With () : (ab)2 = ab × ab
Without () : ab2 = a × (b)two = a × b × b

305, 1679, 306, 1680, 1077, 1681, 1078, 1079, 3863, 3864