system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Common Core math?

I grew up and went to school in the era before Common Core math, can somebody explain to me why they are teaching math this way now and hell it even makes any kind of sense?
gpt
In the past, the focus of math instruction was on calculating ("doing math"). This was especially important in the era before ubiquitous technology with a calculator in everyone's pocket. It also meant that being taught one way to perform a calculation was enough, such as the traditional way to multiply two multi-digit numbers.

But the catch was that there was one method for every topic, and those methods didn't connect well across the years. Learning how to multiply numbers in 3rd grade and learning how to, say, multiply two polynomials in 11th grade were taught using completely different methods, even though the underlying structure is actually the same. As you can imagine, this led to students feeling overwhelmed trying to remember dozens of different math techniques separately instead of understanding the structures they shared in common, like trying to memorize the spelling of a word without knowing how it's pronounced.

The Common Core State Standards are an attempt to do two things: (1) Teach multiple ways of performing early math tasks, to both increase learning for students across many different learning preferences and to stress underlying themes and structures instead of just processes. And (2) to emphasize what mathematical thinking is really about - how to think about mathematics and not just how to do it - by adding what are called "standards of mathematical practice" to the content. These include things like "I know how to look for and make use of repeated structures and patterns" which is a skill that leads to math success in every year of school whether it's addition or simplifying fractions or graphing parabolas.

The real catch is that many math *teachers* weren't educated to think this deeply about math, especially elementary school teachers who usually don't get degrees in math. So if they're anxious about math to begin with and barely comfortable teaching basic processes, trying to teach for deep understanding using multiple approaches that they never practiced themselves in school is a real, difficult challenge (and the reason for so many frustrated and derisive Facebook memes posted by teachers and parents!).