I need to propagate a few uncertainties for logarithmic numbers, using the following two formulas:

For:

where:

uncertainty in result

uncertainty in numbers used for calculation

numbers used for calculation

AND

For:

where:

uncertainty in result

result of calculation

uncertainty in numbers used for calculation

My question is, what exactly are the 0.434 and 2.303 values for? I assume they're to counter something that log calculations add?