Almalieque wrote:
Catwho wrote:
Every time I see a thing getting shared that demonstrates how "hard" Common Core is, I read through the word problem and determine that it's more or less how I've been doing math in my head since I can recall.
You don't always have a pen and paper handy if you want to figure out what 657-293 is on the fly. But if you know that you can add -7 to the -293 to make it a nice round -300, then subtract 657-300 to get 357, then just add the 7 back again to get 364, you get a nice fast solution to the problem without having to write it down. That's the skill Common Core is trying to teach.
They just don't do a very good job explaining to teachers how to explain it to kids (or parents.) Smiley: rolleyes
You don't always have a pen and paper handy if you want to figure out what 657-293 is on the fly. But if you know that you can add -7 to the -293 to make it a nice round -300, then subtract 657-300 to get 357, then just add the 7 back again to get 364, you get a nice fast solution to the problem without having to write it down. That's the skill Common Core is trying to teach.
They just don't do a very good job explaining to teachers how to explain it to kids (or parents.) Smiley: rolleyes
I figured this out in like middle school. It really simplifies things.
That method was taught to us in 3rd and 4th grade in my first Elementary school. They started with examples of adding any number to 99. Just add 100, then subtract 1. Then expanded on to other numbers. Rounding up/down to something easy, then just subtracted or adding what you added or subtracted. It's just a simple application of algebra. A+B = A+X+B-X. It just wasn't explained using algebra until reaching middle school around 7th grade.