First your take 55 and divide it by 20 to find out have many feet is equivalent to 1 inch. 2.75 feet is equivalent to 1 inch. then you divide that by 8 to find your 1/8 inch equivalent. 2.75/ 8 is equal to .34 feet per 1/8 inch.
U would measure it with the teaspoon and the 1/6 teaspoon you would need 2 use the 1/2 teaspoon 4 times to get 2 teaspoons and the `1/6 teaspoon 4 times to get 2/3.