# Conversation and Fun > Just Conversation >  math Brain Teaser

## Joann Raytar

This riddle must be Done In Your Head and Not using paper and a pen or a calculator.  Do this in your head as you read it!!  *Don't Cheat now!*

Take 1000 and add 40 to it. Now add another 1000.
Now add 30. Add another 1000.
Now add 20. Now add another 1000. Now add 10.
What is the total?

----------


## Maria

4100. Is that right? Is it a trick?

----------


## hcjilson

I came up with 5000! Who knows....its a riddle right? I was never good with these anyway  :) :)

------------------
Harry J

----------


## Cindy Hamlin

I got 5000, too!  Harry if we crash and burn we do it together!  :)

----------


## HenryB

I'm with Maria on this one......4100 it is.

----------


## Blake

2100!

:-p

Blake

[This message has been edited by Blake (edited 04-02-2001).]

----------


## chip anderson

If we cannot even agree on simple addition no wonder we are so far apart on other subjects.   Opticians are supposed to be good mathematicians (I am not), but God save us all, maybe Ole G.Gordon is right about the public schools.

5000

----------


## Homer

First I'm with Maria, however out of sensitivity to others who may feel that they are right also, I will concede that I may be wrong, nevertheless, I really feel that I am right too, so I am hoping for some compassion from the 5000 club.

Isn't the really question about whether we really feel that  2 + 2 = 4 and that we can be truly comfortable with that sum?

----------


## Blake

5000?  Wish you guys worked for my bank!

I can see where the 4100 comes from, but I still say 2100 (one word in the riddle is the key).

But Chip, some people make you wonder sometimes.  Some rocket scientist called in to our local paper happy because daylight savings time gives us extra daylight.

Blake

----------


## Night Train

I've done it twice and both times I get 5000.

----------


## JennyP

4100.

----------


## hcjilson

Will someone who has posted 4100 please end my misery and tell me how???Im lousy at math, I'm lousy at riddles....I'm a good whiner though  :)

------------------
Harry J

----------


## Joann Raytar

5000 is incorrect.

I will give you guys one more guess before I post the correct answer.

----------


## Pete Hanlin

I'm going to "take" a guess and agree with Blake...  2100!

Pete

----------


## Maria

Take 1000 and add 40 to it. 
(1040)
Now add another 1000.
(2040)
Now add 30. 
(2070)
Add another 1000.
(3070)
Now add 20. 
(3090)
Now add another 1000. 
(4090)
Now add 10.
(4100)
What is the total?
I still think it's 4100, and I've added it up about 15 times now. I don't see what Blake means about the riddle word, but I shall blame this on the cultural differences if I'm not right.  :)
Where does 2100 come from?

----------


## hcjilson

Thank you Maria! I don't know why I was so surprised- I may not any good at Math, but I'm a smashing Anglophile! Rule Britania!

------------------
Harry J

[This message has been edited by hcjilson (edited 04-03-2001).]

----------


## Cindy Hamlin

Can I say DUHHHHHHHHH!  I guess we are a little more dense in the colonies!

----------


## Pete Hanlin

I think the riddle word (if there is one) is the word "take."  In arithmatic, "take" usually refers to subtraction.  Thus, if you "take" 1,000 you start out with -1,000...
+40=-960
+1,000=40
+30=70
+1,000=1070
+20=1090
+1000=2090
+10=*2100*

Then again, it may be that I've read too much into the question (which is about normal for me  ;) ) and the "trick" was to arrive at 4,100 and not 5,000 -which is easy to do if you do it in your head... (I say that to assuage folks like _Night Train_  :) ).

Pete

----------


## Blake

Yep, Pete, that's what I was thinking... I guess it depends on what your definition of "take" is ;-)

Okay, Jo, you put it up - what's the answer we were supposed to come up with?

Blake

----------


## Joann Raytar

Maria's answer would be correct, 4100.  When we add in our head our brain forgets to carry the one after adding 10 to 4090.

----------


## chip anderson

I just hate it when those mathematicly astute on optiboards show me what a dumba-- I am.

Chip

----------


## hcjilson

I get it now!....Harry forgets to Carry! :)

------------------
Harry J

----------


## Joann Raytar

When I first did this I made the same mistake as the 5000 folks.  Yep 4090 + 10 = 5000 in my brain.  I was positive it was 5000 until I wrote it out on paper and realized my brain wasn't carrying the 1 correctly.  I wonder how many other items our brains just fill out automatically.

----------


## Cindy Hamlin

No Harry Carry, huh!

----------


## jcmnbogey

:Cool: 
4100

4090+10=4100

"take 1000 and add 40 to it" implies we are starting with 1000
hope i'm seeing things in the right light

----------


## Danimal2

Take 1000 = (-1000) so, -1000 + 40 +1000 +30 +1000 +20 +1000 +10 = 2100.

----------

