History of Magic and Muggle Studies are both indeed non-magical classes. History of Magic is probably more immersed in the study of magical topics than is Muggle Studies.
Astronomy is another discipline taught at Hogwart which straddles the magical/Muggle worlds. Study of the stars.
I can see Divination as being mostly non-magical, at least how its described in canon. There is the reading of tea leaves (non-magical equipment), presumably the reading of tarot cards and the like, and reading crystal balls (the one item that I think could possibly have more magical properties). Hermione describes Divination as "a very woolly discipline" in Prisoner of Azkaban, which I interpret to mean she doesn't find it particularly useful or possibly non-magical or less magical. She sees Divination as subjective. Frankly, in the end, Divination came in use when Professor Trelawney provided crystal balls as weapons during the Battle of Hogwarts. Note: I see the ability to receive Harry's prophecy on Trelawney's part as separate from the actual course material taught in Divination the class. Certainly there are many "psychics" who hang out their shingle all over the Muggle world, not to mention religious practices that use symbols, interpretation of texts, objects, and incantations as part of their worship.
Herbology might include some knowledge that could cross over into the Muggle world, such as growing potions ingredients that both magical and Muggle folk use for making potions and herbal tinctures/supplements respectively. If you look at the list of known potions ingredients at the Harry Potter Lexicon, you will find ingredients that are just naturally occurring in the world, and are not strictly magical plants or herbs.
ETA: The study of Ancient Runes might help prepare for a career in archeology, if a magical child were to take that route. Runes are found in the Muggle world and are not exclusive to the Wizarding world.
I think that Squibs would need a strictly Muggle education in order to get by in the world. Ron Weasley confides that a family member (a cousin, I believe) is an accountant but the family "doesn't talk about him much." Otherwise, magical folk seem to stay fairly insular, working in magical jobs and careers.
REPHRASED: Some professions, whether wizarding or Muggle, require advanced math and/or science. Canon does not explain how a magical child would receive advanced instruction in math or science at Hogwarts, or should their chosen career path call for it. Perhaps advanced skills are taught through apprenticeships (canon mentions wandmakers study under other wandmakers to learn wandlore) or specialized on-the-job training (such as an Auror might receive). Many people -- magical or not -- are able to go day-to-day using only addition, subtraction, multiplication, division, and fractions, even though they've been taught advanced math, such as algebra, calculus, and trigonometry. How relevant advanced math will be will vary profession to profession. Most children -- again, magical or not -- are familiar with basic math by the time they leave elementary school, so this kind of learning would precede a Hogwarts education, as Hogwarts students are either in Muggle primary schools or homeschooled prior to going to Hogwarts (no mention is made of all magical elementary schools in the Wizarding world). The skill of writing is reinforced at Hogwarts through essay writing; it's just that the subject matter is magical, not Muggle.
Also, (POTTERMORE SPOILER)
Pottermore states that some students are allowed to study Alchemy at Hogwarts and receive special instruction in that discipline. Alchemy could be related to chemistry, which could be bridged between the magical and Muggle world.