How to make the output of ScientificForm computable

Question

I am trying to extract the mantissas of a list of numbers using the ScientificForm and then do some operation on them. However, it seems that the output does not act like a number and is not computable (this is also noted in the documentation). I was wondering if there is a workaround for this?

Here is an example:

list = ScientificForm[#, NumberFormat -> (#1 &)] & /@ {12.34,23.45,345.6}

Then Total@list returns 1.234 + 2.345 + 3.456 without computing the sum.

Answer 1

What I meant is since you have the original list, why not do the operation on it? Like this (see also comment by Syed above on MantissaExponent)

list1 = {12.34, 23.45, 345.6};
m = Last /@ MantissaExponent /@ list1 
list1/10^(m - 1)

Total[%]

Instead of doing

list = ScientificForm[#, NumberFormat -> (#1 &)] & /@ list1

And then trying to do Total on the above, which will not work since it has wrappers around them.

Answer 2

The general idea is to do computations and display the result using the Form wrapper of choice. Compare the following for instance.

blist = ScientificForm /@ {12.34, 23.45, 345.6}
Total[blist]
Total[blist[[All, 1]]]

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so I would say extract the first part.

list = ScientificForm[#, NumberFormat -> (#1 &)][[1]] & /@ {12.34, 
   23.45, 345.6}

or

list = First@ScientificForm[#, NumberFormat -> (#1 &)] & /@ {12.34, 
   23.45, 345.6}

If you look at the TreeForm output for individual numbers, it is clear that you need the first part.

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2 list

{24.68, 46.9, 691.2}