No, it means every 10 cards in the total sum of cards in your trash and the cards in your opponent's trash.For example, if you have 15 cards in your trash and your opponent has 9 cards in their trash, the total would be 24. Therefore, you add 4000 to the maximum this DP-based deletion effect can delete, and you can now choose any number of your opponent's Digimon so that their DP total is 7000 or less.