chili powder

Question

 if 1 tablespoon of chili powder weighs 1/4 ounce then how many tablespoons can be measured from a 1 pound jar?

Answer 1

We want to convert a 1-pound jar into tablespoons.  Use the multiplicative identity (that is, 1) to convert units without changing the value:

       (1 pound)*1

       (1 pound)*((16 oz)/(1 pound))

       (1 pound)*((16 oz)/(1 pound))*((1 tablespoon)/(1/4 oz))

       (1)(16/1)((1/(1/4)) tablespoons                     [cancel other units]

       (1)*(16)*(4/1) tablespoons                   [to divide by fraction, invert and multiply]

        64 tablespoons