title: MS Excel: how to sum scientific notation excluding bracketted variance values looking like X.XXE-01 (XX.XXE-01)?
body: <p>I have cells of data in excel formatted as follows:</p>
  <p><a href="https://i.stack.imgur.com/kjf6b.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kjf6b.png" alt="image of cell formatting in excel" /></a></p>
  <p><em>There is a need to have both the number and bracketted number in the same cell.</em></p>
  <p>I wish to create four more cells containing the percentage contribution of each cell to the sum of the non-backetted numbers.</p>
  <p>I.e the sum in the first new cell would need to be 3e-05/(3e-05 + 1.6e-05 + 6.02e-05 + 5.71e-04) x 100. Rounding issues do not matter.</p>
  <p>I have limited experience in excel, and help would be <em>very</em> appreciated.</p>