How to turn off wifi on iPad?

There's the standard way to turn off in Settings, but also through Control Center. Tap on the little Wi-Fi symbol and it will turn off Wi-Fi until "tomorrow".

Access Control Center on your iPad - Apple Support

Use and customize Control Center on iPad - Apple Support

Settings>WiFi>Off

Thankfully, that involved very little math.

"Math is hard!" - Barbie

The Control Center option actually doesn't turn WiFi off. It simply disconnects the device from the current network. WiFi remains enabled. And, if you move to another known WiFi network, the device will connect to that network.