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True, but you'll save lots of time if you keep the ability to do simple math in your head.
Classmates always wondered how I could finish the tests before the time limit while they weren't even finished when the bell rang. Well, who'd have thought, entering 20*5 into your calculator takes longer than just doing it in your head? I don't want to know how long these people take shopping groceries now that everyone has a calculator in their pocket.
20*5 sure that’s easy. But are you actually going to opt for a piece of paper to long divide 4/17 if presented with the need?
If I need more than 2 decimals of precision, I'd use the calculator. But by the time I type it in I already know to expect an answer of about 0.23. If the calculator give me anything else, I'll redo it more carefully.
A good student knows enough basic math to know whether or not their calculator did what they thought it did, or if they mistyped something, had it in the wrong mode, missed order of operations, etc.
Gonna be honest my guy I don’t believe you did 4/17~=0.23 in your head. And if you did, great for you but, most people can’t do that.
I did, and you can too. Here's how: 4/17 is about 4/16 = 1/4 = 0.25, but a little less because 1/16 is greater than 1/17. The error term is about 4/(16^2) or 4/250, so subtract about another 2 hundredths to 0.23.
Or my thinking:
4/17 is less than 4/16 (0.25) but more than 4/20 (0.2). It's on the fatter side of that difference, so I would go with 0.225 with some rounding... If I need a better answer than 0.22 or 0.23, I'll use the calculator