my bandwidth tends to be clogged with thoughts of boobies and beer; significant exposure to the latter having severely compromised my cache-dumping ability.
not enough registers. I think that's my problem, anyway.
Wow... impressive! I also have used the method you mentioned when doing multiplication and always wondered why they didn't teach it that way in school.
Wow... impressive! I also have used the method you mentioned when doing multiplication and always wondered why they didn't teach it that way in school.
And exactly how does that make you smarter? What does the ability to do math on the fly actually gain you? Has practically 0 real world usage and benefits nothing to you other than your arrogance.
I was listening to a radio program recently that got into certain aspects of how our brains work:
http://www.radiolab.org/2008/nov/17/
Go to about 4:40 and they talk about a study from way back in the 50s that tried to determine how much we could memorize in the short term. They found that it was around 7 digits, +/- 2 digits. Holding a lot of numbers in your head at once requires training. You can improve your ability to recall numbers in the short term but you have to use it constantly.
We like people like you. You end up getting fleeced by CC companies, car dealerships, and grocery stores, thus putting more money into circulation and stimulating the economy.
The "Dumb and proud" act is a little annoying, though.
Hey now! The other reason being....you were taught math by lazy stupid Americans.So, in summary, why is mental math so hard for you? Because you're a lazy, stupid American.
Hey now! The other reason being....you were taught math by lazy stupid Americans.
Its the way our brain is wired. Some people with autism have their brains wired differently and can process raw numbers and images far better than the average person can.
Of course, there are tricks that you can apply, but in the end, they are just cheap tricks. They don't work to improve or grow neurons involved with number processing.
Can I work at improving mental math? Or is it just inherent.
But, you've stumbled upon a huge reason as well - in general elementary education teachers aren't that good at math. One of my friends attended a fairly well respected school in the area for education. He took the "math for el ed majors" course. One day, he showed me a test - "what grade level is this?" "I'm not positive, since they keep shuffling the curriculum around. But, I'd say it's right around 4th grade, give or take a year." "Guess how the students did. Not kids - the other kids in my class at <university>." "I don't know... just about everyone aced it, a couple people missed a question out of carelessness and rushing through it?"
Almost every one in his class failed the exam.
Other places would approach it like this: 30 times 50 = 1500. Easy to remember 1500. 4 times 50, add to the 1500. Now you're up to 1700. 7 times 30, add to 1700 is 1910. Just have to remember 1910. Lastly, 4 times 7, and add that to the 1910 = 1938.
Can you improve over where you are now by working and exposing yourself more to it? Absolutely. Can you become this kid? No!Can I work at improving mental math? Or is it just inherent.
Can you improve over where you are now by working and exposing yourself more to it? Absolutely. Can you become this kid? No!
http://www.huffingtonpost.com/2013/...tistic-14-year-old-nobel-prize_n_3254920.html
Do it like a computer in fast simple iterative steps.
So you want them to do math in binary using logic gates?
I'm assuming you were raised in the U.S. One reason it's hard to do is the algorithms that children are typically taught in this country for doing things like multiplication. For example, when multiplying 34 times 57, US children would multiply the 7 and 4 first, get 28, have to carry the two, multiply the 7 and 3, add the two. Then put a zero down to the right on the next line as a place holder, and multiply the 5 times the 4, carry the two, 5 times 3 and add the 2.
Other places would approach it like this: 30 times 50 = 1500. Easy to remember 1500. 4 times 50, add to the 1500. Now you're up to 1700. 7 times 30, add to 1700 is 1910. Just have to remember 1910. Lastly, 4 times 7, and add that to the 1910 = 1938.
In the first algorithm, it takes multiple steps to arrive at the first number and multiple steps to arrive at a 2nd number before you add them together. In the latter algorithm, you're keeping a running total while still doing one multiplication at a time.
Cue about middle school age. The brain has developed to the point where it can handle more abstract concepts (like variables.) Now we're teaching Algebra, and it takes a couple days of teaching before the kids get good at multiplying something like (2x+3) and (4x-5). Kids in other places think, "shit, this is what I've been doing for 4 years. This is nothing new." This, in part, explains some of the differences on standardized testing. Through, I think it's 4th or 5th grade, U.S. children compare quite favorably, then they fall way behind.
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Also, fucking calculators. If you had a little robot that carried absolutely everything for you, you never even had to lift up a glass to your mouth to drink, in a couple of years, you'd be asking, "why is it so hard to carry a bag of groceries." Without practice, you can't do arithmetic very quickly. The more often you use a calculator for simple arithmetic operations, the slower your brain gets at doing that mental arithmetic.
Further, if you don't have a calculator, you start learning tricks. 87 times 93? Why, that's just 8100 minus 9. Why? Because it's (90-3)(90+3); the product of conjugates which is 90²-9. Or, in a calculus class, faced with finding the area under a curve using the midpoint method (midpoint of the base of a rectangle determines the x-value at which you determine f(x) for the height of a rectangle). It's fairly common on those problems to have to find 6.5², 7.5², 8.5², etc.
6.5 squared: 6 squared (36) plus 6 = 42. Tack on a .25 to the end: 42.25
7.5 squared: 7 squared (49) plus 7 = 56. Tack on a .25 to the end: 56.25
8.5 squared: 8 squared (64) plus 8 = 72. Tack on a .25 to the end: 72.25
At which point you might see a pattern. "Hey, it goes up by 14, then 16, I'll bet the next one is 18 higher." Though the pattern might be a little harder to discern if f(x) is something like 2x²+x+5; but no more difficult to do in your head.
Why it works? Again with the algebra. (x + 0.5)(x + 0.5) = x² + x + .25
Note: if you did (10x + 5)(10x + 5), you get 100x²+100x+25. So, the pattern is the same without the decimal.
As your mind learns more of these tricks, you look absolutely amazing to people who can't do mental arithmetic. You might say, "but you're doing..." Doesn't matter - it's still mental arithmetic, it's just that with a fluency in Algebra, you have a lot more algorithms at your disposal. And, with practice (not relying on a calculator from 4th grade on), you get quicker and quicker at identifying which tricks work on which problems.
Fun problem: I'll get a class to give me digits of a 9 digit number. Once I have a lot of kids shouting out numbers, it's easy to be selective for the 2nd number to make it 142857143. I can multiply any 9 digit number times 142857143 faster than the students can type it into a calculator (only to find out that the display on the calculator isn't large enough. So, when they get a rounded number in scientific notation, we have to turn to a computer to verify my answer. But it's simple: I multiply by 142857143 indirectly. First I multiply the 9 digit number by 1000000001 (which just makes it an 18 digit number with the first 9 digits repeating. So, if the first 9 digits that the kids give me are 234897561, then the new number is 234897561234897561. Then, divide by 7. Long division - in your head. (omg, it's soooo hard, since you haven't done long division in your head in 20 years.)
7 goes into 23 3 times (write down the 3, mentally carry the 2; 7 goes into 23... )
So, in summary, why is mental math so hard for you? Because you're a lazy, stupid American.
Yeah... that's not in the state approve curriculum. We're going to need you to lecture out of this book and then give the students these worksheets. If you keep teaching non-approved material, we're going to fire you.
Can I work at improving mental math? Or is it just inherent.