Hi Tim and Chris,
Thanks for the answers.
First to set the recored straight - I am already using STACK in my course. Also, we already discussed the Units Issue in:
I am currently using units in my questions, and I built some functions to support units analysis which includes:
1) The ability to transform all units to one specific units system, to compare answers (such as in your example above for the m/s to Km/h).
2) the ability to compare the units of the students answer with the correct one.
3) the ability to choose the list of equivalent units.
Other features I would like to have:
--> I have not build the ability to differentiate between (m/s) and (Km/h) as I see no scenario in which I would like to correct a student for working in his own chosen units system - and if he "mashes" together to unit systems, it will reflect itself in the final answer.