Q: what function keys are used to get the number pad

The number pad should be functional independently of the other keys. You should be able to use the keys as is to input numbers and math symbols.

I might add that my prior answer is for the extended keyboard with the built-in number pad. If you have Apple's compact bluetooth keyboard that does not have a built-in number pad, then you will not have this option. In this case you can purchase a separate bluetooth numberpad, or purchase an extended keyboard with a built-in numberpad.

sadtidds wrote:

 

what function keys are used to access number pad

If you mean you have the extended keyboard, but the number pad doesn't work, you may have enabled the ability for them to control the mouse instead of the numbers (very handy if your mouse/trackpad isn't working).

Go to System Preferences > Accessibility and select Mouse & Trackpad in the sidebar.  If the Enable Mouse Keys box is checked, remove it.

Also click the Options button; on the next window is a box allowing you to click the Option key 5 times to turn the Enable Mouse Keys on or off.  If that's checked, that may be how you got this turned on.