No need to be rude.

Calculators are great when you need an exact answer or the problem has a lot of pieces. A lot of problems just require estimates, and many high schoolers and adults can’t do that.

If you ever work outside where your hands can get cold, wet, and/or dirty, you’ll understand that using your phone for math is not always convenient.

You’re right. I’m a high school teacher (not math), and very few of my students are capable of doing arithmetic without a calculator. I can’t imagine how tedious it must be having to pull out a calculator every time you need to do basic arithmetic.