Makes perfect sense from the pics and the scales.
You have three ranges, 0-10, 0-15, and 0-20, on the metric side. Each range depends on how far you extend the wrench. (I suspect the bold is the suggested range)
On the range, each graduation is 1mkg, so you have a full scale of 10mkg on A range, on the C its 25mkg. Of course all this is critical to the wrench being extended to exactly the correct length, and then having the graduation scale in exactly the right place.
You just need to stop torquing when the pointer and the wrench main beam are separated by the correct number of mkg.
Now figuring out mkg is your problem. The ft lbs is easy here, as are inch lbs.