Mark has 10 fewer cards than Michael so Mark has 100 cards - 10 cards = 90 cards.
So, Lloyd has 90 cards / 3 = <<90/3=30>>30 cards.
All three of them have 90 cards + 30 cards + 100 cards = <<90+30+100=220>>220 cards.
Thus, they need to collect 300 cards - 220 cards = <<300-220=80>>80 more cards.
#### 80