My first scientific calculator was the Casio FX-992S which I bought it in Secondary 2 in 1998 when I was 14 years old. It lasted me through my secondary education, polytechnic education as well as my 2 years and 2 months in national service. It finally broke down during my 2nd year in university in 2007 just few hours before my exams! The calculator lasted me for 9 years! After it broke down, I borrowed my brother scientific calculator, he is also using the Casio FX-992S and he got it during his secondary school days. I predict it will have another 3 more years lifespan as he is going to national service soon if his calculator followed the timeline of my calculator.
I went to NUS Co-Op to see if there is any calculator to buy, to my surprise the FX-992S still exists! However there is another modal also from Casio called the “Natural Textbook Display” FX-991ES. I was contemplating between the both, the price difference is about S$3. End up I went for the good old trusted FX-992S for S$29.70.