I am a student and I have purchased citizen ct-500 for 600 two years ago I working from then. This calculator has a very good built quality. Each buttons has a good space from each other and comes with two power source that is inner battery power amd solar power. It is a twelve digit calculator ideal for office and home use. It also comes with check and correct plus auto replay and error recalling feature
But I am facing a problem now that is its button are getting hard and it hurt my fingures for using continuosly. It also comes with reset button.
This is good one for daily use.