Spreadsheet Exploration

I have been using a spreadsheet program of one kind or another for many, many years.  They are a very versital tool when working with a lot of data that needs sorting or a repetitive formula.  A perfect example of this is part 7 of this assignment.  Place four numbers in the first row as follows:A B C D.  Each of these needs to be in a separate column.  For each successive row replace the entries by the absolute value of the difference of the entery just above and the entry just to the right in the previous row.  In the foruth position use the absolute value of the difference of the fourth and the first row as follows: |A ?B|  |B ? C|  |C ? D| |D ? A|.  This is not difficult to create on a spreadsheet program.  Fill in the first row with the desired first numbers.  On the second row create the formula needed to do the math for each cell.  The critical things to remember were to not forget the absolute value commands and to make sure that A is subtracted from D and not column E.  Once the second row is set up, it can be copied down the page as far as desired.  The row numbers and column numbers will shift appropriately with the copy function.

Here is an example of the above problem:
 
 

Column A	Column B	Column C	Column D		Column A	Column B	Column C	Column D
55	236	2	1713		10	12	14	16
181	234	1711	1658		2	2	2	6
53	1477	53	1477		0	0	4	4
1424	1424	1424	1424		0	4	0	4
0	0	0	0		4	4	4	4
0	0	0	0		0	0	0	0
Column A	Column B	Column C	Column D		Column A	Column B	Column C	Column D
1	2	3	4		10000	1000	100	10
1	1	1	3		9000	900	90	9990
0	0	2	2		8100	810	9900	990
0	2	0	2		7290	9090	8910	7110
2	2	2	2		1800	180	1800	180
0	0	0	0		1620	1620	1620	1620
0	0	0	0		0	0	0	0

I created eight different sets of numbers to better show how this problem worked.? If you have a desire to manipulate the data more click here to access the worksheet. (Assignment12.xls)? Notice that most sets of numbers get to zero in four or five rows.? But there is one that takes six and one that takes seven.?Every row does eventually have zeros in all four columns.? The row before the end logically has the same number every column also.? What is the largest number of rows that you found before hitting zero?? After much playing around mine was 13.? And that took some playing around with first one column then the others.? What made it easy was the fact that, except for the changing the first row, I did not have to do any of the mathematics.
 

Column A	Column B	Column C	Column D
27	38	44	7
11	6	37	20
5	31	17	9
26	14	8	4
12	6	4	22
6	2	18	10
4	16	8	4
12	8	4	0
4	4	4	12
0	0	8	8
0	8	0	8
8	8	8	8
0	0	0	0
0	0	0	0