The Touch pad has a number icon on the top right where you can activate and deactivate the NumberPad mode. It uses an LED light, so when you tap the icon it will light up and is ready to use NumberPad mode. I use it all the time and even when the NumberPad is on, I can still do other functions like scrolling up and down and other gesture functions without engaging with the numbers. It is very efficient!
Here is a video explaining about it if you want to check it out. https://www.youtube.com/watch?v=8NKvpiejCMo