23+45= (10+10+3)+(10+10+10+10+5)=(10+10+10+10+10+10)+(3+5)=60+8=68
"WHAT"
23+45= (10+10+3)+(10+10+10+10+5)=(10+10+10+10+10+10)+(3+5)=60+8=68
"WHAT"
"WHAT"
Yeah, the Mrs. is teaching "decomposition" to kindergartners. The have to understand that 12 is one set of ten, and two more. I get confused when she tries to explain it to me.
The 9-year-old has probably done this crap.
It was all finger painting story's and nap's.
Getting a better understanding of the big picture really does help in the long run, but it has to go hand in hand with the traditional method, IMO.
My favorite mental shortcut is teaching percents. If you can find 10% (which is, of course, simple), you can find 20%, 30%, 40%, etc, by just multiplying it by 2, 3, 4...
I remember my mom teaching me the multiply by 9 shortcut. They never taught it in school, but I always used it when I needed it.
9x8 = subtract 1 from 8, then count how many it takes to get to 9 = 72
Easier (for me) than just memorizing the multiplication tables.
My FIL pooped!!
It worked for me.
9x6 = subtract 1 from 6 (5) then count (from 5) how many it takes to get to 9 (4) = 54
My FIL pooped!!
Is this newsworthy for some reason?