The normal rate of speaking is between 120 and 150 words per minute. At that rate you would need a minimum of 600 words if you spoke rather slowly and only for 5 minutes to 1500 words if you spoke faster for the entire 10 minutes. To know how fast you read get a newspaper and a timer or watch with second hand. Have someone time you for exactly 1 minute while you read aloud in a normal voice. Count the number of words read and multiply that by 5 or 10 to get the most accurate count. MS Word has a word count feature that will help determine the length regardless of font.