They are all numeric characters, exactly as you have written it.
Exactly as you have done in the question: 45000
3.918208205 X 10^11 I think but I'm stupid so probably wrong
It is: 666 = DCLXVI which means 600+60+6 = 666
12.00 merely means 12 and in Roman numerals it is XII
Group1 is considered Alpha-Numeric because it has both alphabet characters and numeric characters.
They are all numeric characters, exactly as you have written it.
ruby
In Excel all columns default numeric characters to numbers.
It is the same as 350
00.9
The term alpha characters refers to those characters that are letters. This is in contrast with numeric characters, which are numbers.
Letters and numbers only. No symbols, punctuation, or special characters. IE abcdefghijklmnopqrtsuvwxyz1234567890
9.00 is the same as 9
1975
Without the leading zero: 9057606387
Exactly as you have done in the question: 45000