I have a template that has a field from an aggregate model in it (as well as some additional text). How can I limit the number to 2 digits after the decimal?

Skuid UI only formulas field don’t have a MID function. So, if you don’t know precisely how many digits the number will be, you can’t use a UI only formula field. Your options would be a snippet (custom field renderer probably), or a Salesforce formula which you could then include in your model and template.

If you do know how many digits your number will be, you could use the LEFT function in a skuid ui only formula field http://help.skuid.com/m/models-conditions-filters/l/378313-ui-only-fields