How to SUM bold numbers in one cell?

[penkuk]

Hello!

I was trying to find post for this one, but couldnt.
So i got numbers in one cell (B3) 4.3 ± 0.4 and in the next cell (B4)18.5 ± 0.5 and so on ...
Is it possible to sum them? with some code to MVB ? or somehow else ?

something like this, and in the blank space i want to sum them

 

[Fluff]

It doesn't work for me, maybe because i got merged cells ?

Merged cells will be the problem, get rid of them.