Why does my sim card show no number it states unknown

ianstra1100 The new sim and plan would  be data only if that's what you ordered.

As you say, it is a standard sim with unlimited calls/texts in the smarty plan.

I can see no reason why you should not be able to put it into any phone that is compatible with Smarty 4G VoLTE protocol and get it to work normally.

I am wondering whether the mobile number does not show on the iPad because the device does not have capacity to make calls. An internet search suggested that this may be the reason. I cannot check it because my iPad is wifi only.