There's no way for the iPad to talk directly to your Android phone; they're using different operating systems. It sounds as though you just expected that that would somehow happen and, frankly, if you had an iPhone, it would.
There are several different ways to do it indirectly, at some remove, things like working in a complicated way through Google, in a not very less complicated way through and Exchange server, and perhaps there are some other specialized apps and sites out there that would provide the service you're looking for.
You have to look at your own systems and requirements and see which approach might best suit you.