Change 004200 to scientific notation

Answer 1

As leading zeros are not normally written when leading zeros are written I would normally expect a decimal point at the beginning (either after/before the first zero) but with 004200 there are also trailing zeros which would not normally be written after a decimal point; thus it is difficult to determine if the number should be as written or there is a missing decimal point.

I'm going to guess there is a decimal point missing at the beginning after/before the first zero:

0.04200 = 0.042 = 4.2×10^-2

.004200 = 0.0042 = 4.2×10^-3

Answer 2

004200 = 4200 = 4.2*10^3