Math as a concept in the three-dimensional world with the relative consistency that is experienced by most, If not all, Known creatures, Was discovered. FORMULAS used to find certain values for greater understanding of the world, SYMBOLS such as numbers and calculative signs, And VALUES/FUNCTIONS of those symbols were all invented.
The modeling of human DNA as a double helix, Mandelbrot's sets, And "hello world", All of these were realized on the basis of observable mathematics. Newtons apple would be the most simplest of examples for discovery. Notably Calculus was created under a similar stay at home order to todays trying times.
Math is the guiding principle of the universe. Math has always existed. This is because math basically is the fundamental cornerstone of science. Science would not have existed without the laws of mathematics. Science is discovered not invented. Therefore, Math is also a law of the universe, Discovered not invented.
Plus, You can't escape math class by saying it is man made.
There are mathematical models that do not describe any of things, Existing in real life. Rules of classical geometry based on axioms, That seem intuitive. However, There are metrics based on other unprovable statements, And derived, Using the same logical operations, And that is still mathematics. N-dimensional spaces, When N is more than 3 are still mathematics. Mathematics is large than nature and it could not be discovered.
There are certainly behaviors and relationships in the universe that we can observe, Test, And have repeat. But these things are not inherently "mathematical. " They are just natural phenomenon that occur and we have found ways to measure and observe them. Math was the tool and language invented to interpret this information. But still just a framework invented by humans.
They way nature functions isn't determined by the math we are taught in schools today. Math is not a guiding principle that the universe must follow, Its just a tool used by humans to represent those principles that guide nature. Since its more of a tool we use to communicate and represent these relationships and fundamental theories, Math was invented, Not discovered.