That's kind of how I taught my daughter to add subtract multiply and divide, except in her head not on paper.
Now to multiply 247 x 38, I would actually multiply 250 x 40 to begin with. That's an easy calculation of 10,000. Then I would subtract 500, since we're dealing with 38 and not 40, so we're down to 9,500. Then I would subtract 114, since we're dealing with 247 and not 250 (3x38 = 114), arriving at 9386. I did that in 3 steps, vs 10 steps the traditional way.
But you forgot to add 1 to 114 then 115+5 then 120 +10 Gee how do you people not see how ridiculous that method is
But you did not do that the first day you learned multiplication in the third grade. AND...this is EXACTLY what the many step process is teaching the children to do, "Break it down." Now they are trying to teach children the way that many have figured it out over time.
Because isl's answer is correct! If you have a better way, please demonstrate...and keep in mind, he did it in his head, not on paper or a calculator.
I remember Dean McCameron in my first programming class in 1974 explaining that computers are fast and accurate but totally stupid and that it is necessary to break every decision down into a series of simple "if then else" logical statements for them. "Computers can't even multiply," he said, "but they can add so fast that it greatly resembles multiplication."
15 years ago there was a big push for a "new math" that involved getting away from rote learning and teaching in the form of "real life" situations. I agreed completely with the notion that kids new "facts" but had little understanding of concepts - in reference to application. I was on board with the "new" curriculum -but not for abandonning the flash cards altogether. I fought for (and did get) a balance of the two based on the premise that in a real-life situation, having the facts memorized had a place as well.
