(HP12C) Always a number further !

[Nihotte(lma)]

Thanks for your practical suggestions, rprosperi !
Thanks for your link too, SlideRule !

For your last remark, rprosperi, I can explain you that the original program starts with asking how many items the user wants to memorize. The calculator first gives the list and then the user key in back the numbers, one after one. Each time, the user makes a mistake, the program pops up an alert but it continues until all the list is over.
At the end, the user gets a good or bad grade !