Change Dimension to Measure in Data Manager Summary Tab

[rwb139]

Hi all,

I'm currently trying to change my dimension to a measure so that I can take the sum of these amounts. However, I can't change from a dimension to a measure on the summary tab and I'm not sure why. Does it have something to do with the "$" "," or "." in my numbers? Thanks for any help! 

[rwb139]

Here is where my issue is. Trying to add these I get 0's on everything: