Casio HR-8TMPlus Calculator "8tm change" Questions

...change the tax calculation from 5% to 6.8% I have looked over the instructions 4-5 times and tried a different way to calculate the tax+ to get 6.8% but the casio hr-8tm still goes to default at 5% ...

...change the ribbon on my casio hr-8tm calculator? Do I just drop the replacement ribbon in? Place the roll on the wire thing at the back (I don't think it matters which way round); push the paper ...

8TM. I came here and read all the before mentioned solutions. Then the idear struck me. Instead of cutting the paper even all the way across the roll, I cut it slanted on the sides and straight across