A Math trick

Using your knowledge of algebra to do a Math trick. This is video 18 of 51 in the solving equation series. The next three series are "Word Problems", "Factoring" and "Graphing". What is the most valuable online VIDEO of ALL TIME? Find Out Now! - http://wadn.weblo.com/1d2de84bd8165c6b/gateway?adId=884579e2d85b9302

Category:

Howto & Style

Tags:

• mathematics
• trick
• equations
• solving
• series

[ghostrider1718]

it's not a trick.. because the real math is 24 divided by 2 and result 12. if you think of a number you will extract it anyway in the end, and when you double your number you divide by 2 after the next step. it's not a trick, just simple math.

[minkusbc]

@ghostrider1718 No, you and I know it isn't a trick, but please remember the audience this is aimed at. A 13 or 14 year old grade 8 student just learning algebra thinks this is "magic", I know, I've done on many classes over the last 41 years of teaching (1970 - 2011). Then, when you show them why it works, they get a bit of a different feeling about algebra. A lot of math "tricks" have algebra behind why they work.

[razorplade]

pick random number: x

double it: 2x

add 24: 2x+24

divide by 2: x+12

subtract original: x+12-x = 12

as good as pick a number, subtract it from itself, add 12, WOW u got answer 12 

[minkusbc]

@razorplade Please remember the audience this is aimed at. A 13 or 14 year old grade 8 student just learning algebra thinks this is "magic", I know, I've done on many classes over the last 40 years of teaching (1970 - 2010). Then, when you show them why it works, they get a bit of a different feeling about algebra.

[Ultranerdguy]

@minkusbc

13 or 14 year old just learning agebra? I figured this out when I was 9!

[minkusbc]

@Ultranerdguy: Super, your school system must be very advanced. Here in British Columbia, Canada, algebra of this type is started at about grade 8 (12 to 13 years old). I imagine, then, you are doing Calculus by about 15 or 16?

[Chris3836]

"TRICK"

Think of a number.

Double it. (ADD IT)

Divide by 2.

Subtract by original and you'll always get zero. =)

[minkusbc]

@razorplade Please remember the audience this is aimed at. A 13 or 14 year old grade 8 student just learning algebra thinks this is "magic", I know, I've done on many classes over the last 40 years of teaching (1970 - 2010). Then, when you show them why it works, they get a bit of a different feeling about algebra.

[suffl94]

think of a number

subtract it.

you get zero ;D

[BrillyGracey]

that trick is neat. maybe awesome,.

[leezhijiang]

How to get back the number u think

[TheBBoyPhysicx]

type gift before youtube url

[domesticboerdom]

i got 65

[buddypas]

how 'bout this: think of a number,multiply by 2, then multiply THAT with 3 and divide it with the original number and.....u get 6!