General question about a part drawing....

I am fairly new to SW (took an intro class); I'm working on replicating some part drawings that someone sent me for practice, and I have a question about dimensioning.  I am seeing some dimensions that say:  15,7   or     2,2     etc.....What does the comma between the numbers mean?  I am sure it's not a decimal point, definitely commas.  Thanks for helping out a noob!SolidworksDrawings And Detailing