How do logarithms work?
ROW/COL	B	C	D	E	F	G	H	I
4
5
6		Number 1	Number 2	Result of Multiplying	Mathematically we can say:
7	Number	10	10	100	=10*10
8	Power of the number	1	1	2	=1+1
9
10	Notice we get the same result by multiplying the numbers as we do by adding the power of the numbers.
11	The power of the number is also its exponent. By default we do not write the power if it is 1.
12
13	Works for any numbers			Result of Multiplying	Mathematically we can say:
14	Number	100	10	1000	=100*10
15	Power of the number	2	1	3	=2+1
16
17	We also that we can write:		1,000,000
18	as	=10*10*10*10*10*10
19	or		=10^6	(remember an ^ means raised to the power)
20
21	Thus
22	Number	1,000,000	1,000,000	1,000,000,000,000	=1000000*1000000
23	Power	6	6	12	=6+6
24
25	In fact the spread sheet might use:		1E+12	to represent the number.
26	As you can see the E+12 means move the decimal point 12 space to the right and you get the answer.
27
28	It would not be hard to figure the exponent for any number which is an even power of 10
29
30	So then we can see that		100,000
31	is the same as		=10*10*10*10*10
32	or		=10^5
33
34	Rather than count the number of 10's needed to get the number a spreadsheet provides a function to do this
35
36
37		Number	Log of number (or the number of 10s)	Formula
38		10	1	<=LOG(C38)
39		100	2	<=LOG(C39)
40		1000	3	<=LOG(C40)
41		10000	4	<=LOG(C41)
42		100000	5	<=LOG(C42)
43		1000000	6	<=LOG(C43)
44
45	The log function is particularly helpful if we wish to find the power of 10 when the number is not exactly a power of 10
46	We can write	12,345
47	as	=10^4.09149109426795
48	or the log of	12,345	= 4.09149109426795
49
50	Works for any numbers
51		Number 1	Number 2	Result of Multiplying	Mathematically we can say:
52	Number	12,345	678	8,369,910	=12345*678
53	Power of the number	4.091491094	2.831229694	6.922720788	=4.09149109426795+2.83122969386706
54
55
56	In days before electronic calculators and computers logs were commonly used because addition is easier than multiplication
57	Tables of logarithms were available as were slide rules which were base on logs.
58
59	To reverse the process, to convert a logarithm into a number, you need to do the opposite.
60	Again for even powers of 10 that is not difficult. For uneven powers of 10 use the spreadsheet power symbol (^) to do it.
61
62	Log of a number is:	4.091491094
63	Exponent form:	=10 ^ 4.09149109426795
64	The number is	12,345	<=10^C62
65
66	Therefore	10^(log(Number)) = Number
67	Example	Number
68		12,345	12,345	<=10^LOG(C68)