screen expands on 3 taps - how do turn this off?

[AMASTR9]

I made some adjustments to my settings on my LG G3 recently and something I changed now allows the screen to expand to several times it's normal size if I tap the screen 3 times. I use my calculator  A LOT and invariably I wind up with a blown up screen. How do I turn this annoying feature off?

THanks in advance!

AS

[SuzyQ]

Go to Settings on the phone, accessibility, then explore what is set there.  It may be under magnification, or zoom settings.