5

Try pasting =10**-2 into a cell in MS Excel. After pressing Enter, it turns it to =0.1. I can't seem to find any documentation for **, but it appears to be a pretty odd exponentiation-like operator that cannot be used in an Excel formula (e.g., =A1**A2 is invalid`).

If this operator is not an exponentiation operator, what is it?

(N.B.: mathematically, 10-2 = 0.01, not 0.1)

Mike T
  • 41,085
  • 18
  • 152
  • 203
  • 2
    Why the close votes? I think this is a perfectly valid question: referencing an undocumented behaviour, defines a use case that can be replicated, explicitly asks a question about that behaviour. – Mark Baker Jan 31 '12 at 09:14

2 Answers2

6

** is the same as E

=4E3 == 4**3 == 4000

Roger
  • 420
  • 5
  • 8
  • No because `.1` * `.1` would be `0.01`, not `0.1` – Mike Christensen Jan 30 '12 at 23:01
  • 3
    not the same as ^ or power. this is not an operator, which is what is confusing. It is functionally equivalent to typing the letter "E" between two numbers. – Roger Jan 30 '12 at 23:05
  • 2
    @MikeChristensen, this matches F.J.'s examples exactly. I think Roger nailed it. This is an alternative entry method for scientific notation. – Tim Mayes Jan 30 '12 at 23:07
  • Thanks Tim, that was much more eloquent than my explanation :) – Roger Jan 30 '12 at 23:41
5

It appears that A**B shifts the decimal point of A to the right by B positions, or mathematically A**B is equivalent to A*(10^B).

This is basically a scientific notation shorthand, so 1.23**-2 would show up as 1.23E-02 in the cell, so not only does it perform the shifting as described above but it will change that cell's category to 'Scientific'. Note that this is only the case if you enter the value into the cell without a leading =, so =1.23**-2 would keep the current default for the cell and display 0.0123.

In the case of 10**-2, the decimal point is being shifted to the left by 2 positions (since B is negative), resulting in 0.1.

Here are a few examples:

1**-2 => 0.01
1.2**2 => 120
.5**1 => 5
Andrew Clark
  • 202,379
  • 35
  • 273
  • 306