# What do you know from this 2+2=5 video?

My friend asked me what is the meaning of this video. It states that only "genius mathematicians" can understand. Well, I am not a genius so I don't know what is it talking about. Personally, I don't think that this is a video that expresses some profound thinkings. However, here is the link.

Hope you all can give some comments! Note by Christopher Boo
6 years, 7 months ago

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This is from George Orwell's "1984", where Winston Smith, under torture and interrogation, is forced to say that party apparatchik O'Brien is holding up 5 fingers, when he knows he's only holding up 4 fingers. I don't think it takes a "genius mathematician" to understand how ideologies tend to force people into thinking and saying only certain proscribed things. Even though "1984" is supposedly a futuristic tale, information and thought control goes back thousands of years, as means of maintaining political power.

What's probably true is that "genius mathematicians" are adverse to rote or standardized thinking, which is a major problem today in American schools pretending to be teaching "math".

- 6 years, 7 months ago

- 6 years, 7 months ago

My dad taught me this when I was 8

$-20 = -20$

$= 16 - 36 = 25 - 45$

$= 16 - 36 + \frac{81}{4} = 25 - 45 + \frac{81}{4}$

$= 4^{2} - 2 \times 4 \times \frac{9}{2} + ( \frac{9}{2} )^{2} = 5^{2} - 2 \times 5 \times \frac{9}{2} + ( \frac{9}{2} )^{2}$

$= a^{2} - 2ab + b^{2} = a^{2} - 2ab + b^{2}$

$= (a-b)^{2} = (a-b)^{2}$

$= ( 4 - \frac{9}{2} )^{2} = (5 - \frac{9}{2} )^{2}$

$= ( 2 + 2 - \frac{9}{2} )^{2} = (5 - \frac{9}{2} )^{2}$

$\implies 2 + 2 - \frac{9}{2} = 5 - \frac{9}{2}$

$\implies 2 + 2 = \boxed{5}$

P.S. Of course it is incorrect ;) There is a very minute trick

- 6 years, 7 months ago

So THAT's what O'Brien was trying to explain to Winston Smith. Four fingers is indeed FIVE.

- 6 years, 7 months ago

Yep it is

- 6 years, 7 months ago

Thanks!

- 6 years, 7 months ago

It can be said that 2+2=5 but how can u say that if the squares of two numbers is equal than the numbers are also equal...for example, 4=4 but root 4 is not equal to root 4...as it can be +2 as well as -2...good explanation though Muzzafar...I was surprised for a moment...haha!!

- 6 years, 7 months ago

Moreover, u took letter 'a' as one variable but it has two different values which can't be true...One side a=4 and the other side a=5....

- 6 years, 7 months ago

That is why I told

There is a mistake :P ;)

- 6 years, 7 months ago

Actually it is

$( 4 - \frac{9}{2} )^{2} = ( 5 - \frac{9}{2} )^{2}$

$= ( - \frac{1}{2} )^{2} = (\frac{1}{2} )^{2}$

$= \frac{1}{4} = \frac{1}{4}$

- 6 years, 7 months ago

You took same variable ( a ) on both sides but with different value

- 6 years, 3 months ago

Nice video Christopher...!!!:)

- 6 years, 7 months ago

Welcome to my sixth grade classroom, Foundations of Algebra! :D

- 6 years, 7 months ago