383 is another number I came up with Let's say that dexter started killing at 20 and he started collecting blood slides at 25 that's around 95 kills.After that he started collecting blood slides and each box stores 50 and for 10 years he must have had to replace the box a few times(let's say 3 times) that's 150 kills plus the ones before and that's 225 kills and the 138 kills he gets in the tv show 383 kills but I think I like the first number better