Fractions were certainly in the curriculum earlier, but were they learned? I'm sure my high school calculus cohort understood them, but I'm not sure the average

Fractions were certainly in the curriculum earlier, but were they learned? I'm sure my high school calculus cohort understood them, but I'm not sure the average adult can add fractions confidently. Those who don't are going to weigh down any math class after that point. (I'm not blaming people traumatized by early math schooling. I just think there are many.)