This was definitely still taught in my public high school in the 2010s - if they stopped teaching this, it was very recently.
Granted, the teacher that tried to teach me this had no understanding of it themselves and would incorrectly mark answers wrong when they had the correct number of significant digits, so it was pretty botched in my case. Still was attempted in the curriculum though.
Granted, the teacher that tried to teach me this had no understanding of it themselves and would incorrectly mark answers wrong when they had the correct number of significant digits, so it was pretty botched in my case. Still was attempted in the curriculum though.