OUCH - that's scary.
My daughter was taught how to use a calculator, and they do use them occasionally for certain work, but they are generally not used and they are not permitted to bring them to school. I had to refresh myself on long division when she was learning it because once I learned short division, I never went back to long.
I pretty much stick to paper and pencil with math, because I can rarely find a calculator around here and I have no clue how to use the one on my phone.
I have no problem with letting students use calculators, but they should first be required to master the basics.
I also use paper to calculate as often as possible just to keep my old brain sharp. Math has given me fits all of my life; my brain is geared more toward language and the visually aesthetic.