Question

Recently in the United States, there were about 300,000,000 cell phone users. That same year, there were about 5.7*10^9 cell phone users worldwide. About how many times larger was the number of cell phone users worldwide than in the United States?

Answer 1

US: 3 x 10^8
5.7 x 10^9 / 3 x 10^8 = 19