Difficulty squaring numbers

[Guest]

Hoping someone can help me out here - I'm working on a project where I need
to include some squared numbers. It seems that regardless of the function or
formula I use, my answer is never actually right.

I've formatted all cells as numbers, so I don't think that's having an
impact. However, say that in cell C4, I have the number '20'. In D4, I type
any of the following:

=POWER(C4,2)
=PRODUCT(C4,C4)
=C4^2

Regardless of which formula I use, I end up with the answer 416.16, despite
the fact that the square of 20 is 400.

Short of just entering =20^2, is there anything someone can spot or suggest
that might help me fix this?

 

[David Biddulph]

The number in C4 is not 20. If you format it as General, or as Number with
a non-zero number of decimal places, you'll see that it is 20.4, but you've
formatted it to display only the 20.
If you really want to get only the 400, you could replace the C4 in any of
your formulae by ROUND(C4,0). Another option is Tools/ Options/
Calculation/ Precision as displayed, but that would apply not just to that
cell and may therefore cause unexpected and unwanted problems elsewhere so
is not generally recommended.

 

[Tyro]

For simple multiplication, including squaring, it's easier on you and faster
in Excel just to type =C4*C4. David got the number 20.4 by simply
determining the square root of 416.16. When answers don't look quite right,
it's often helpful to display the number as a number with a few decimal
places as David suggested. I've seen a number display as such 6.8 and as I
increased the number of decimals there were still 0's after the 8 until I
got around 12 places of decimal and then it displayed as
6.7999999999999999999. This calculated number was being compared with a
typed-in number of 6.8. The comparison resulted in not equal.

Tyro