I don't recall ever using a slide rule at school. The requirement was to write out all the steps in solving a problem.
I still have an ancient book of log, sine, and cosine tables that I almost wore out with use.
My daughters' school, on the other hand, required all students to purchase a specific model of a Texas Instruments scientific calculator.
I guess a lot depends on the education system. I used to pay sick calls to an elderly gentleman who had a very odd preoccupation with the Imperial Japanese Navy. He'd talk about it endlessly, leaving me with a splitting headache. Of the many stories he loved to tell and re-tell was that IJN gunners were trained to do advanced mental mathematics. So advanced that they could mentally calculate shell trajectories. For this reason, he insisted, IJN ships could fire at coastal targets in the middle of the night, whilst American and other ships had to wait until daylight so that they could calculate range with optical instruments.
That didn't make sense to me, and the IJN didn't fare so well in the Pacific War, but I didn't have the heart to challenge him.