Scaling values using the value_factor is too difficult. This should simply be a multiplier, not a factor/exponent of 10 that you want to scale values by. For converting MB to GB or GB to MB it makes it much easier, and for anything that is scaled by 10s then you just multiply by the factor of 10, 100, or 0.1, or 0.01 and it's plain and simple. There should be a pre-scale offset and a post-scale offset for anyone wanting to convert temps between C and F. Then you could pretty much convert between any units anyone should ever need.