text: using scientific notation:? a red blood cell is 0.000007 m in diameter. there are about 20,000,000,000,000 red blood cells in a 125-ib person. if all of the red blood cells were lined up end to end, how long would the line be? multiply 0.000007 (7x10ˆ2) by 20,000,000,000,000 (2x10ˆ13) the answer is 140,000,000 (1.4x10ˆ8) meters