Yup, this is what parents are complaining about when they say math has changed. Before, math was primarily about rote memorization. You just memorized that 9+7 is 16. There were multiplication tables you were expected to memorize and regurgitate ad nauseam. Sure you could count it out on your fingers, but that only works for numbers under 11. For anything above that, you just referred to your memorized addition, subtraction, multiplication, or division tables. But this also meant that numbers outside of those tables were really difficult to do in your head, because you were poorly equipped to actually calculate them out.
Common core math is attempting to make math easier to do in your head, by teaching the concepts (rather than promoting rote memorization) and helping students learn shortcuts to avoid getting lost. 9+7 is 16, but it’s also 10+6 or 8*2, which are much easier to visualize in your head without counting on your fingers.
You’re either very lucky and were in a school that went against established norms, or you’re young enough that you were taught the “new” math that boomers hate. Because this is the new math.
Boomers, GenX, and elder millennials were primarily taught via rote memorization. You simply memorized the times tables, and committed “8*3=24” to memory. You didn’t calculate it every time. You just memorized the tables, regurgitated them ad nauseam to appease the teachers, and then referred to those memorized tables for any multiplication you needed to do.
For reference, this is the times table I’m referring to. Our quizzes/tests required you to fill out the entire thing in less than 5 minutes:
We had to fill this out multiple times per week. The goal of the time limit was to force you to memorize it, instead of calculating it out every time. You simply didn’t have time to calculate each one out. Then once you had it memorized, if you ever had to do 8*3, you would just refer to your memorized times tables for it.
But the issue with this is that it doesn’t teach you how to actually do the math in your head, it just teaches you the times tables. You aren’t calculating it out each time, so you don’t develop any shortcuts or methods to make it easier. If a teacher ever saw you turn 9+7 into 10+6, they would bust out the red pen and start slashing. Even though 10+6 is undeniably easier to do in your head, the teachers weren’t concerned with that; They wanted to know that you had memorized what 9+7 is. These memes are primarily aimed at the millennials and GenX with ADHD, because they were the ones who got bored of rote memorization and started coming up with shortcuts (which then got docked points on their quizzes.)