Do this in your head
 

Do the math in your head.

Take 1000 and add 40 to it. Now add another 1000.
Now add 30. And another 1000.
Now add 20. Now add another 1000. Now add 10.

and No caculator!

Re: Do this in your head
 

OK, 5000, not difficult to do off the top of my head.

Re: Do this in your head
 

are you so sure its not that diffcult to do it off the top of ur head?? ;) and plus ure a mentor...that would make me even laugh moore:P

*can't stop laughing*

Re: Do this in your head
 

i got 4100 out of my head....

if i missed something here...let me know....i am easily confused when i'm tired...

Re: Do this in your head
 

Just because I'm a mentor doesn't mean I'm immune to mistakes! ;)

It's actually 4100. After I added it up again I got 4100.

Re: Do this in your head
 

Same here... after some rethinking, I also got 4100.

Re: Do this in your head
 

4100 first try. /me is smart :)

Re: Do this in your head
 

hehe..u're not the only one...everyone on my msnlist got it wrong:P they all got 5000 even i did too:P

Re: Do this in your head
 

Yup I got 4100 also...

Re: Do this in your head
 

Yeap 4100, I got it the first try but i think the part where you get confused is when you get to 4090 and then add ten if you are trying to do it fast it is very likely you will say 5000.

Its a pretty good one.

Dave

Re: Do this in your head
 

Oh man.. you got me the first time. But then again I'm not a math major, and I suck at anything math related. But the second attempt... I got it... so I guess it's "2nd time is the charm" now... :D

Re: Do this in your head
 

...i got 63.


...no wait, 4100. i get 4100.

Re: Do this in your head
 

well my first answer was 42, since it is the answer to everything.

Then I actually did some math and it ended up being 42 + 4058 or 4100.

Re: Do this in your head
 

You can just add the 1000's together and then add the smaller numbers together. it makes it a ton easier. I got 5000 first also ::embarassed::

Re: Do this in your head
 

Hm... I'm muy confused...

Did it twice in my head and got 5000. Did it once on calc and got 4100. :confused:

Re: Do this in your head
 

Same here.

Re: Do this in your head
 

yeah got 4100 the first time. try keeping the 1000's apart then add the smaller numbers. you get 5000 by mixing up their places and what not.

Re: Do this in your head
 

Oops... you found what I did. Remember kids, 90 + 10 != 1000. ;)

Re: Do this in your head
 

I got 4100 first!!! =D Man I rule. :cool:

Re: Do this in your head
 

did it in my head and got 4100...

Really not that hard, but its a good way to confused others...

Re: Do this in your head
 

I got 4100 my first time, but I spend nearly a week trying to figure this out when I first saw it.

Re: Do this in your head
 

I got 4100.

I had the exact same problem on my precalc exam, got 5000, and got it wrong. Ive learned to add since then.

Re: Do this in your head
 

yeah quite a good question to test peoples ability of adding. obviousely alot of us cannot add yet we build successful robots. Makes you wonder sometimes how that works out :)