> The Gateway Arch in St. Louis, MO is approximately 630 ft tall. How many U.S. half dollars would be in a stack of the same height? Each half dollar is 2.15 mm thick. number of half dollars: Each half dollar has a mass of 11.340 g. How much would the stack of half dollars from the previous question weigh? mass: What is the value, in dollars, of the same stack of half dollars? value: dollars The 2017 U.S. gross domestic product (GDP) was valued at 19, 390, 604, 000 dollars. How many Gateway Arch-height stacks of half dollars are needed to match the GDP in value? number of stacks: g