First let me explain what marketing is in the business world. Marketing is the field of understanding WHO ("customers") a company is selling to and HOW (what "strategies" will they use) to reach the MOST customers.
I'll give you an example: If I wanted to sell a car, I could go into the middle of the street and yell "Hey, who wants to buy a car?" That would be a terrible marketing strategy (HOW to sell this car), but if I advertised that this car was for sale--with a photo and some words that say how great the car runs and that it's for a low price, and placed this advertisement online in a few places where people (WHO) buy cars, that marketing strategy is much smarter and would probably sell the car pretty fast.
People who are marketing professionals spend their time figuring out WHO are their customers, depending on what they're selling, and HOW to best reach them as much as possible (like advertising the sale of a car where people who want to buy a car would look online). It all depends on what you're selling. In any "marketing material," whether it's an ad, a verbal or written presentation, a commercial on TV, a blog, a press release, whatever way is used to make sales happen, marketing professionals think of the best ways to accomplish sales.
Also, marketing executives have to know WHY their product or service that they want to sell will sell. That is, what makes the car special so someone would want to buy it. Maybe it's in mint condition? Maybe the price is low and it is an SUV with plenty of room and has a beautiful interior? Whatever the reasons are that make the product or service that a marketing professional must sell as their goal, it is also their responsibility to KNOW THESE REASONS WHY.
There are different parts to marketing, but that's it in a nutshell, Aisha, and math really isn't a big part of marketing at all, except for setting the most reasonable, yet the highest possible PRICE on an item or service, since business is based on profit, unless the business is a "non-profit" organization, which is a small percentage of businesses. Pricing is determined through research and ultimately understanding the VALUE of what you're selling, which depends on how special and important the REASONS are as to WHY the customers would buy this product or service (We call this the "demand") and how many are available (We call this the "supply").
The only part of marketing that involves math is called "marketing research analytics," which others can do, if you don't want to be involved with math. I almost never, in 40 years, have become involved in math, yet pricing is always an issue, but again, pricing is figured out by the factors I've described above.
I hope this helps you, Aisha! Let me know if I can be of more help.
All the best,