The Flesch Reading Ease score for each of these books has been calculated in Word. A LOWER score indicates the text is more difficult to read. The theoretical simplest text would score ~120 (e.g. Green Eggs and Ham by Dr Seuss). 100.0 - 90.0 could be read by most 11 year olds. 70.0 - 60.0 could be read by most 13-15 year olds. Scores below 30.0 would mostly be understood by graduates. The Flesch Reading Ease takes into account the average length of sentences and average number of syllables per word. It does not necessarily correlate with comprehension level (ie you could read something you don't understand or vice versa).