If you know that 64 equals 16 ounces than you can divide 64 by 16 to get 4. This means that one ounce equals four pretzels. Then you can multiply 1 oz by 4 and 4 pretzels by 4 to get 16 pretzels that equal 4 oz. If 4 pretzels equals 1 oz then 1 pretzel equals 1 oz divided by 4.