Krista

Question: Could someone please explain what the title means and what numbers have to do with anything? I'm not a native English speaker and I don't get it.

Answer: It's like a paint-by-numbers, where a picture is outlined on a board, and each little piece of it has a number corresponding to a different color of paint. You paint in the spaces based on what the numbers tell you. Murder by numbers refers to the boys following all the "rules" about how to create the perfect murder: choosing a victim at random, etc. They're murdering based on what they've been told is the right way to do it.

Krista