How do I "double-click" on my ipad?

The only thing I can think of which one might double click an iPad for is the power button to approve purchasing an app?

That's what I suggested above. You don't double tap the screen. You double tap the power button, which you are being shown by where the bouncing double tap message appears on the screen.

Bengals66 wrote:

How do I "double-click" on my ipad?

to do what?"