Select three sections in the book at random, making sure that the passages include 100 words each. Draw a chart on a sheet of paper with three columns and six rows. Apply these headings to the columns: "Number of Sentences" and "Number of Syllables." The rows will be "First 100 Words," "Second 100 Words," "Third 100 Words," "Total" and "Average." You may create an average with more than three passages for a more balanced average, but only three is necessary.
Count the number of sentences in each 100-word section and write them down in the appropriate places on the chart. Count the number of syllables in each section and write those down in the appropriate columns on the chart. Calculate the totals and averages for each column by adding them, and then dividing by three. Write the averages in the chart. There is no need to count initials and numerals when counting the passages.
Take the average of the number of sentences and number of syllables and look for those numbers on the Fry Graph. Place a dot on the graph where these two averages intersect for the score of the book in question. If your scores seem to have too much variations, you may collect more passages for a new average.