Hotmath
Math Homework. Do It Faster, Learn It Better.

Exponent Tables and Patterns

There are many interesting patterns to be found in the tables of powers of whole numbers.

Powers of 2
Powers of 3
Powers of 4
2 1 = 2 3 1 = 3 4 1 = 4
2 2 = 4 3 2 = 9 4 2 = 16
2 3 = 8 3 3 = 27 4 3 = 64
2 4 = 16 3 4 = 81 4 4 = 256
2 5 = 32 3 5 = 243 4 5 = 1024
2 6 = 64 3 6 = 729 4 6 = 4096
2 7 = 128 3 7 = 2187 4 7 = 16384
2 8 = 256 3 8 = 6561 4 8 = 65536
2 9 = 512 3 9 = 19683 4 9 = 262144
2 10 = 1024 3 10 = 59049 4 10 = 1048576
 

One thing you may notice are the patterns in the one's digits. In the powers of 2 table, the ones digits form the repeating pattern 2 , 4 , 8 , 6 , 2 , 4 , 8 , 6 , ... . In the powers of 3 table, the ones digits form the repeating pattern 3 , 9 , 7 , 1 , 3 , 9 , 7 , 1 , ... . We leave it to you to figure out why this happens!

In the powers of 4 table, the ones digits alternate: 4 , 6 , 4 , 6 . In fact, you can see that the powers of 4 are the same as the even powers of 2 :

4 1 = 2 2 4 2 = 2 4 4 3 = 2 6 etc.

The same relationship exists between the powers of 3 and the powers of 9 :

Powers of 3
Powers of 9
3 1 = 3 9 1 = 9
3 2 = 9 9 2 = 81
3 3 = 27 9 3 = 729
3 4 = 81 9 4 = 6561
3 5 = 243 9 5 = 59,049
3 6 = 729 9 6 = 531,441
3 7 = 2187 9 7 = 4,782,969
3 8 = 6561 9 8 = 43,046,721
3 9 = 19,683 9 9 = 387,420,489
3 10 = 59,049 9 10 = 3,486,784,401

The powers of 10 are easy, because we use base 10 : for 10 n just write a " 1 " with n zeros after it. For negative powers 10 n , write " 0. " followed by n 1 zeros, and then a 1 . The powers of 10 are widely used in scientific notation , so it's a good idea to get comfortable with them.

Powers of 10
10 1 = 10 10 0 = 1
10 2 = 100 10 1 = 0.1
10 3 = 1000 10 2 = 0.01
10 4 = 10,000 10 3 = 0.001

10 5 = 100,000

(one hundred thousand)

10 4 = 0.0001

(one ten thousandth)

10 6 = 1,000,000

(one million)

10 5 = 0.00001

(one hundred thousandth)

10 7 = 10,000,000

(ten million)

10 6 = 0.000001

(one millionth)

10 8 = 100,000,000

(one hundred million)

10 7 = 0.0000001

(one ten millionth)

10 9 = 1,000,000,000

(one billion)

10 8 = 0.00000001

(one hundred millionth)

10 10 = 10,000,000,000

(ten billion)

10 9 = 0.000000001

(one billionth)

 

Click here for more names for really big and really small numbers .

Another consequence of our use of base 10 is a nice pattern between the negative powers of 2 and the powers of 5 .

Powers of 2
Powers of 5
2 5 = 1 32 = 0.03125 5 5 = 1 3125 = 0.00032
2 4 = 1 16 = 0.0625 5 4 = 1 625 = 0.0016
2 3 = 1 8 = 0.125 5 3 = 1 125 = 0.008
2 2 = 1 4 = 0.25 5 2 = 1 25 = 0.04
2 1 = 1 2 = 0.5 5 1 = 1 5 = 0.2
2 0 = 1 5 0 = 1