Except in my version of the real world, I work with my hands in a messy environment and being able to do simple math, conversions and, fractions in my head is a critical necessity.I suck at doing math in my head, even basic math, and these weird ways don't make it any easier. I usually hate playing math oriented card games for that reason since it makes me feel like an idiot, it's even worse trying to do it in your head when under pressure. While it's obviously good to understand how to do this manually I think the easiest is the traditional way of stacking the numbers then you do one column at a time. Carry over the 1 etc. That style.
But in the real world you would feed that data in a computer. Whether it's a calculator, or a computer program, etc.
I think the easiest is the traditional way of stacking the numbers then you do one column at a time. Carry over the 1 etc.
That brings up another pet peeve of mine, "manglish." The term I made up to define words like minuend and, subtrahend. I understand mathematical relationships very well but, start talking about those relationships using manglish and my eyes glaze over and, I start thinking homicidal thoughts.
Subtract subtrahend from 10.
example from OP picture.
11-7= 4; 10-7 = 3
15-7=9; 10-7 = 3
15-6=9; 10-6 = 4
you're using the number line approach which works just fine but, is not the method shown in the op.Both number are just the difference (distance) from 10. Add them to get the answer. Pretty sure this is exactly how I do subtraction in my head.
137-88 = 37+12 = 49
you're using the number line approach which works just fine but, is not the method shown in the op.
You are adding two numbers, in the op, the number is subtracted from ten and the added the the number in the ones position. A small difference of perspective.Yes, it is. It's exactly what is being taught in the OP.
You are adding two numbers, in the op, the number is subtracted from ten and the added the the number in the ones position. A small difference of perspective.
I'm all for different perspectives when learning math but, this method adds an extra step and another chance to make a mistake. It's new math fail.
Ah, thanks.
Subtract subtrahend from 10.
example from OP picture.
11-7= 4; 10-7 = 3
15-7=9; 10-7 = 3
15-6=9; 10-6 = 4
As already explained by MagnusTheBrewer..
The general approach is to present mathematical concepts using different perspectives because not everyone learns the same way. Teachers spend a great deal of time learning different techniques such as this to better teach and communicate with their students. Overall, it's a good thing.What's the purpose of this kind of math teaching? It does not inspire anything.
What's the purpose of this kind of math teaching? It does not inspire anything.
Great.... what's 13 * 13 and how do you know that's right? No calculator.When I was in class, we MEMORIZED things like multiplication between the numbers 1 and 12 (and every combination in-between). We were speed-tested, too.