The first thing when adding fractions is to find the common denominator.
Fractional math used to be taught in elementary school.
Most “college” students don’t know what a common denominator is. That’s the problem right there.
The other thing they don’t know is the sequencing... (My Dear Aunt Sally...)
I went to grade school from 1962-70. HS 1970-74
No calculators in GS. They weren't around. We learned math the old fashion way. Pencil, paper and scrunching up forehead.
No calculators in HS. They were just coming around and really expensive. We used slide rules.
This is what a slide rule looked like, for the youngsters;
Most college students and even some graduate students don't understand decimal. When asked to explain they usually say, "Everything works backwards to the right of the decimal."