I disagree. I use estimations all the time when shopping.
If I have only a limited amount of money with me at the time, I keep a running total of estimates in my head to see just how much I can buy on that trip.
It also has allowed me to catch mistakes in pricing or the way the cashier rang up an order.
One time the bill came up about $20 off what I had estimated and when the cashier checked the receipt, it turned out someone had entered the wrong amount into the computer system for green beans and was charging about $50 a pound for them.
When I was getting my degree, my science professors encouraged us to use estimates to see if we were close in our answers.
“If I have only a limited amount of money with me at the time, I keep a running total of estimates in my head to see just how much I can buy on that trip.”
I think we need of definition of “estimate”. I add up items while shopping also, but mostly by rounding all cents to ten cents to avoid adding pennies in my head, and then rounding up to dollars fairly often. But then I add up the rounded numbers exactly (at least as well as I can in my head, which is usually accurate). But that’s not really an estimate, but the addition of several rounded numbers.
But this method of “estimating” was not taught in schools years ago. And, like “creative spelling”, and writing which does not count off for spelling, it’s just another method to give a passing grade to students who can’t, or don’t learn to do things correctly.