2.39*10^-18/6.63*10^-34
If the problem is: [2.39 x 10^-18] / [6.63 x 10^-34]
it can be separated into: [2.39] / [6.63] x [10^-18 / 10^-34]
2.39 / 6.63 = 0.360
10^-18 / 10^-34 = 10^16 (subtract exponents)
Answer: 0.360 x 10^16
