HAH! You too, huh? I know, it makes doing concentration challenge annoying as hell when you try to do it and it stops you at 15 seconds because it couldn't recognize the four different ways you draw 5 before it insults you that you have absolutely no concentration at all.
It took me about two and a half weeks before I discover a trick but it may varies depend on the person that are drawing the number. it seems to recognize my 5's better if I write them TIGHTLY and FAST but in some cases, in other training activities it recognize them just fine either way I write it. It takes some experimenting and you may have to cheat a bit on devilish calculations by pressing home and start to start over the training or round until you got writing it down just right down pat. Though I only encourage you to cheat only to get writing the number down, or else you cheat yourself.
OH! Also in case anyone have trouble writing 'I' in activities that requires you to write in all capital letters, be sure to draw the two lines on top and bottom of the 'I's.
I find it ironic how a game that is supposed to make you smarter (mostly with math) can mistake a 5 or 4 for a 9, or a 9 for a 0, or a 7 for a 1, or a 1 for a 2, or a 5 for a 6, or a 2 for a 1, or a 1 for a 7. The list of dumb mistakes the game can make with letters and numbers is endless because everyone has different handwriting.