Rex came to the kitchen table one night last spring with a worksheet, a sharp pencil, and the specific energy of someone who has decided the pencil is optional. He had the good calculator. The one with the little screen that shows the whole line before you hit equals. He was fast. Punch, punch, punch, equals, write it down, next.
"Done," he said, in about four minutes.
Half of them were wrong.
Not calculator-wrong. The calculator did exactly what he told it. He'd typed 3 + 4 × 2 and gotten — well, whatever he got, because he typed it left to right the way you'd read a sentence, and the machine gave him back a clean, confident, beautifully-wrong number. Twelve or fourteen depending on how you fought about it. The right answer was eleven. It's always been eleven. Multiply first. That's the whole game.
What stuck with me is that he wasn't bad at math. He was bad at deciding what happens first. The calculator was flawless. His fingers were fast. What he skipped was the little set of parentheses that live in your head — the ones that say this part, before that part. And no amount of processing speed fixes a missing paren. It just gets you to the wrong answer sooner.
We sat down and did one together, the slow way. I made him draw the parentheses. Actually draw them, ugly little curved marks around 4 × 2, before he was allowed to touch a single button. He hated it. It felt like a downgrade — he had a machine that could do this instantly and I was making him write curly lines by hand like it was 1850. But once the parentheses were on the paper, the calculator became what it's actually for: a fast way to run a plan he'd already made. Not a substitute for making the plan.
People get this part backwards. The calculator was never the thinking. It was always the typing.
I watch this exact scene play out with code more than I'd like. Somebody's got a tool now that spits out a function in four seconds — punch, punch, equals, write it down, next. And the function runs. It's confident. It's clean. It's got nice variable names. It is also, about half the time, solving a subtly different problem than the one on the worksheet, because nobody drew the parentheses first. Nobody sat down and decided what has to be true before the next part, and what has to happen before that. The order of operations is the whole game, and it's the one part the fast machine can't do for you, because it doesn't know which part of your problem is the 4 × 2.
The teams I trust aren't the ones typing slowest or fastest. They're the ones who still draw the ugly little parentheses. They write the failing test first — that's a paren. This behavior, before that code. They name what the thing is supposed to do before they let a single line exist to do it. They keep the order sacred even when they've got a machine that would happily skip straight to a confident wrong eleven-that-says-fourteen. The discipline isn't slower thinking. It's the thing that makes all that speed point at the right answer instead of just an answer, fast.
Rex's worksheet came back the next week with a little star on it. He still uses the calculator. He's still fast. But now he draws the parentheses first, every time, and he doesn't think of it as the slow part anymore. He thinks of it as the part where you decide what you actually meant.
That was never going to be the tool's job.
Don't skip the parenthesis because you've got a calculator. Skip it, and the calculator starts making the calls — and you can't even catch the wrong ones, because you never learned the rules well enough to know it slipped.