from Things To See In Springtime
Take two common nails, or other thin bits of metal, and lay them on a table or board, at what you guess to be exactly one yard (36 inches) apart. Then let the Guide lay the tape-line on it, and, allowing 20 points for exactly right, take off 1 point for each half inch you are wrong, over or under. Do not count quarter inches, but go by the nearest half-inch mark. Do this 5 times, add up the totals, that will give your guessing-length number.
Thus, if your first guess turns out to be 37 inches, that is, 2 half-inches too much, 2 from 20 gives 18 points. Your next guess was 34 inches, that is 4 half-inches too little, 4 from 20 gives 16 points. Your next guess gave 12 points, your next 17, and your last 19. The total, 18 plus 16 plus 12 plus 17 plus 19, equals your number of guessing length or 82.
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