[recursive]

I can do plenty of arithmetic much faster than I could type it on a calculator keypad. That's like saying hardware keyboards are near-useless if you have access to a touchscreen.

[MangoToupe]

I just don't really work much with arithmetic to begin with. Almost 100% of the numerical work I do is symbolic.

[recursive]

All well and good, but don't mistake a practice you don't use as being generally useless.

[MangoToupe]

Similarly, don't mistake a practice you do engage in as necessary!

[palata]

Would you be able to do your numerical work without understanding what an addition or a subtraction is?

I feel like arithmetic is part of the basics to build abstraction. If I say "y = 3x + a", somewhere I have to understand what "3 times x" means and what the "+" means, right?

Or are you saying that you can teach someone to do advanced maths without having a clue about arithmetic?

[recursive]

You can have a solid understanding of "+" without being able to quickly add three digit numbers.