The entire point behind the much maligned New Math is to teach approximate solutions that you can do quickly in your head. It’s the realization that if you want an exact answer, use a calculator, but quick head estimates are still useful.
It was opposed by generations who were told to memorize multiplication tables because they wouldn’t always have a calculator available.
Well you should memorize those anyway. It’s useful all your life for easy calculation. If you want 7 items and they cost $3.50 each, it’s between $21 and $28.
I calculated it in my head without memorising all the multiplication tables. I just realised that 7*3.5 is equal to (7*5+7*2)/2. And that 49/2 is equal to 40/2+9/2. Easy peasy. This is why I failed second grade math, because multiplication tables are only useful for doing operations a few seconds faster.
The entire point behind the much maligned New Math is to teach approximate solutions that you can do quickly in your head. It’s the realization that if you want an exact answer, use a calculator, but quick head estimates are still useful.
It was opposed by generations who were told to memorize multiplication tables because they wouldn’t always have a calculator available.
Well you should memorize those anyway. It’s useful all your life for easy calculation. If you want 7 items and they cost $3.50 each, it’s between $21 and $28.
I check on the calculator I have with me at all times. It’s $24.50
I calculated it in my head without memorising all the multiplication tables. I just realised that 7*3.5 is equal to (7*5+7*2)/2. And that 49/2 is equal to 40/2+9/2. Easy peasy. This is why I failed second grade math, because multiplication tables are only useful for doing operations a few seconds faster.
There’s a much easier way.
7x3.5 is the same as 7x3 plus half of 7. That’s 21 plus 3.5 is 24.5
The funny thing is you did this for the division when you could do it for the entire thing.
Yeah but that doesn’t work when you need it most on “The Price is Right”.