I’m pretty sure I did my math right, hope this helps.
So, Jerome bought a total of 80 cards (8x10) out of which he gave out 30 cards (3x10) so he has 50 cards left. (80-30)
(10,000,000) + (6,000,000) + (100,000) + (7,000) + (300) + (20)
Number???what do you want?