I can teach the kids
Well, good, because that is what you need to do.
Make a large drawing of an Arduino. Label each of the pins with it's number as a digital pin. Label each pin that also serves as an analog pin with it's number. Analog pin 0's number as an analog pin is 0, NOT A0.
A0 is an alias for it's number as a digital pin. Those aliases were introduced ONLY as a way of writing code that could be used on a Uno and a Mega without having to make changes, as long as one understood that the first analog pin had an alias that allowed it to be used as a digital pin, and that the compiler (the preprocessor, actually, would take care of substituting the proper NUMBER in place of the name.
Add labels for all the special uses that some pins have - PWM, SPI, I2C, etc.
You'd be doing the kids a much bigger favor than arguing that printing A0 should result in "A0", not 14.