For younger readers, Australian author Greame Base does a wonderful range of picture books which have stunning illustrations and all most all of them have a mystery to solve or a code to break. While the reading level is not terribly high, the codes can be quite tricky and the themes in them are great. Amazon puts his books at around grade level 3 - 6, so just adjust as necessary I guess!


"If children have interest, then education will follow" - Arthur C Clarke