How to use a Casio HR-150TE calculator. No Manual. Just want to use it for simple math.

SOURCE: how to change the tax calculation from 5% to 6.8%

Hold down the % [SET] key until it blinks > press tax+ > type in the tax rate you want (ie. 8.75) . press and hold down % [SET] key until it blinks.

SOURCE: can not load paper

Solved by itense perseverance!

SOURCE: how do I change the ribbon on my casio hr-8tm calculator?

Place the roll on the wire thing at the back (I don't think it matters which way round); push the paper through the slot at the bottom of the back and then (having taken the clear plastic cover off) push it along the bottom inside at the back as far as you can then start to press the feed button; keep feeding it with your finger and pushing the feed button asnd it should pick up eventually.