Speed Math - Page 6

Ohhh ! i get it now !

lol noob , I've scored 360

If you want to train your brain, I recommend "brain challegne", check it on youtube or somewhere.

hay guise i kan maths to no cheet

lol.

Why isnt it working?!?!?!?

On July 24 2012 14:23 HaiVan wrote: hay guise i kan maths to no cheet

I can beat that

actually 697 is a pretty good fast typing skill !

On July 24 2012 14:45 jeffv8x_-_16 wrote: Show nested quote + On July 24 2012 14:23 HaiVan wrote: hay guise i kan maths to no cheet I can beat that

fak u jef

i just tried it for the first time without reading rest of thread and i was like wtf. LPers are idiots this is ez

On July 24 2012 12:19 waga wrote: Show nested quote + On July 24 2012 12:15 hording wrote: over 75: obvious cheat is obvious I'm quite sure I've got two friends who would score over 90+ (1 of them is Catyoul who used to post here) but I'm 100% sure el_tanque would not score over 10 without cheating

catyoul is def way smarter and better at math than me, but over 90 still seems just about impossible. i was flying with 61. maybe savants who just see numbers in their head or guys who have practiced speed techniques for years can get that high, but normal smart human beings i have trouble seeing anyone get above 75

thought i was clever was gonna post like 86 seemed realistic nice 700's guys

On July 24 2012 18:58 Daut wrote: Show nested quote + On July 24 2012 12:19 waga wrote:   On July 24 2012 12:15 hording wrote: over 75: obvious cheat is obvious I'm quite sure I've got two friends who would score over 90+ (1 of them is Catyoul who used to post here) but I'm 100% sure el_tanque would not score over 10 without cheating catyoul is def way smarter and better at math than me, but over 90 still seems just about impossible. i was flying with 61. maybe savants who just see numbers in their head or guys who have practiced speed techniques for years can get that high, but normal smart human beings i have trouble seeing anyone get above 75

Agreed, 90 seems impossible. 90 Questions/120 Seconds = 1.33 Seconds Per Question.

The time to read the question and to type the answer should take around about a second. Leaves you about 1/3 of a second to figure each question out.

On July 24 2012 18:58 Daut wrote: Show nested quote + On July 24 2012 12:19 waga wrote:   On July 24 2012 12:15 hording wrote: over 75: obvious cheat is obvious I'm quite sure I've got two friends who would score over 90+ (1 of them is Catyoul who used to post here) but I'm 100% sure el_tanque would not score over 10 without cheating catyoul is def way smarter and better at math than me, but over 90 still seems just about impossible. i was flying with 61. maybe savants who just see numbers in their head or guys who have practiced speed techniques for years can get that high, but normal smart human beings i have trouble seeing anyone get above 75

I am not a savant and I could probably do around 80-100. There are certain techniques, little things to do to increase your arithmetic skills.

F.E. any easy one. any 2 digit number by that number (squaring) that ends in 5. will end in -25.
then you take the second number, the one in the hundreds place, and determine the next consecutive number, then multiply.

35^2= 1225
3*4= 12 ends in 25 = 1225

85^2= 7225
8*9= 72 ends in 25= 7225

There are techniques for almost all basic arithmetic equations. I can multiply 3 digit and 4 digit numbers in my head as faster than you can calculate them using a calculator. And thats just multiplication.

Edit: My bad didn't read the last sentence!

more tips pls

What are you guys doing wrong Haivan?

I actually cant get the program to work correctly. Not sure wtf is going on.

On July 25 2012 01:09 MathIsGreat wrote: Show nested quote + On July 24 2012 18:58 Daut wrote:   On July 24 2012 12:19 waga wrote: [QUOTE]On July 24 2012 12:15 hording wrote: over 75: obvious cheat is obvious I'm quite sure I've got two friends who would score over 90+ (1 of them is Catyoul who used to post here) but I'm 100% sure el_tanque would not score over 10 without cheating catyoul is def way smarter and better at math than me, but over 90 still seems just about impossible. i was flying with 61. maybe savants who just see numbers in their head or guys who have practiced speed techniques for years can get that high, but normal smart human beings i have trouble seeing anyone get above 75

I am not a savant and I could probably do around 80-100. There are certain techniques, little things to do to increase your arithmetic skills.

F.E. any easy one. any 2 digit number by that number (squaring) that ends in 5. will end in -25.
then you take the second number, the one in the hundreds place, and determine the next consecutive number, then multiply.


____

yah this is awesome

15^2 = 225
25^2 = 625
35^2 = 1225
45^2 = 2025
55^2 = 3025
65^2 = 4225
75^2 = 5625
85^2= 7225
95^2 = 9025


More tricks would be interesting!

I'll contribute (stolen from reddit )
With big numbers that you're trying to multiply by 5, instead multiply by 10 and divide by 2. This makes it much easier to calculate in your head. Example 88 x 5 = 88 * 10 = 880 / 2 = 440 http://www.reddit.com/r/LifeProTips/comments/u6tje/lpt_request_useful_math_tricks/

"This makes it much easier to calculate in your head.".... no... it does not. It might make it easier for some people that are
better at division than multiplication but just saying "It makes it easier!(TM)" doesn't make it so.

some of my tricks to improve speed on this test


for big multiplications: something like 88x12. i just do 90x12=1080-2x12=1056. it does take a little bit of time and it requires im fast at the basic time tables but its easier than carrying digits and such.

for the tough subtractions: i figure out the ones digit first then estimate. so for example something that takes a bit of time like 164-96 i see ones digit is 8 and then i estimate the other and start guessing. type in 78 then 68 then 58. you get the answer at 68

for big division: i chop off a digit to estimate what its close to and then work back from there. so for example if i got 1056/12, i would chop off the 6 and do 105/6 and notice its close to 9, so i know the answer is close to 90x12 which is 1080. i know its 24 less than that so its 2x12 less than 90x12 so its 88x12.

these tricks can help make things faster but you still have to be very fast with computation to make them work because often you are doing more steps but with rounded and smaller numbers.

and in general a good technique for squared numbers comes from factoring

(x-1)^2 = x^2 - 2x + 1
(x+1)^2 = x^2 + 2x + 1


so say you have 40^2, this is 1600

41^2 = 1600 + 80 + 1 = 1681
42^2 = 1681 + 82 + 1 = 1763

it gets hard after a little while, but starting with something easy and working forwards or backwards isnt too bad

50^2 = 2500
49^2 = 2500 - 100 + 1 = 2401
48^2 = 2401 - 98 + 1 = 2304

another way to look at it is, you add up that number and the next number. so 60^2 = 3600 61^2 = 3600 + 60 + 61 = 3721


factoring in general can help you with all sorts of stuff.

i.e., say you want 46*34. notice that this is the same as (x+6)(x-6) for x = 40. this factors to x^2 - 36. so 46*34 = 1600-36 = 1564. any time you see numbers on equal sides of one number you can do this


57*23 = (40+17)(40-17) = 1600 - 289 = 1311.

it really helps if you know your square numbers up to 30. try writing them out and you will be able to do a lot with it

1,4,9,16,25,36,49,64,81,100,121,144,169,196,225,256,289,324,361,400,441,484,529,576,625,676,729,784,841,900

now you can use that factoring trick for much bigger numbers

@julep
Yeah, Ill post a whole list of all the techniques after I am done with class. Don't have much time right now!

@Daut
Good stuff! I really like your technique multiplying by 12! As for the subtracting numbers I may have a good suggestion.

Work Left ----- Right. It is a lot harder to carry numbers in your head, so working the tradition way in inevitably slower. And break it down.

FE
2 digit numbers-

Ex. 98+57

98+50=148+7= 155


3 digit numbers

Ex. 538+ 327

538+300=838+20=858+7= 865

Just a simple one, but it does help a lot!