Thanks for your interest and comment .
The last chosen number is always highlighted, so I think user won't let lost after resuming the game.
It has a minor drawback though. That is after resuming the game, the user will need to glance through the board to find the highlighted numbers, so s/he will know what to choose next. But that's not a big problem as it will be very quick and if user just want to play for fun (more relaxed); On the other hand, if user wants to gain good scores, it's encouraged that s/he play each session throughly without interruption as it's just a few minutes long
Hope you enjoy the game!