You need to make 2.003 big enough to divide by 9, so multiply it by 10. This will reduce the exponent by 1, so we have 20.03*10^23. Now divide 9.21 into this=2.17481 and subtract the divisor exponent from the dividend exponent to give 10^21. The answer is: 2.17481*10^21 or 2.17481E21.