Perhaps behind the scenes, (like, idk), they’re sometimes given math, English, science and other normal school work? Along with the Wizarding homework?

Wll I guess their parents taught them before they attended Hogwarts. And let's be honest - if you are wizard/witch, you really don't need stuff like math or science.

I think that their parents taught them how to read, write and all these basic things that everyone needs.

What do you really need to know that you don't learn in primary school?

Measurements are pretty straight forward.

So long as you know basic English and can count, add, subtract, multiply, and do basic fractions you're pretty much set.

Arithmancy is the closest thing to math as they're probably going to get and there's Potions. Hogwarts students also had to write essays so there might've been some teaching on that on how to write a proper essay. Other than adding, subtracting, multiplying and etc., they didn't really need math classes.

Chemistry, DADA and Potions would be the closest to science.

In my opinion, when the kids were arriving for the Summer holidays from Hogwarts, they were going to Summer primary shools.