Calculator: raw js or jQuery?

for this project I’ve decided to use VS2015 Community edition (that is free with some very nice features) now that MS seems to be raising their status in the Open Source world.

But that isn’t my question, which is if I mix HTML with some js (in Codepen) I can do it much faster in the development than if I use jQuery (or some js tricks to avoid mixing code) … but can I mix code? in such a simple project I see no big problem with it.
thanx :wink: