Tuesday, July 07, 2009

[puzzle] can you add up

Do this entirely in your head!

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?

If you thought 5000, it's not.

Answer

4100

13 comments:

UBERMOUTH said...

5,010

James Higham said...

Nearly - check the answer.

UBERMOUTH said...

+I can't highl;ight the answer for some reason, but I added 1,000 extra.
So, it's 4,110.

James Higham said...

Getting closer, dearest. Come on, you "kicked Spud's ass", didn't you?

Good to see you back. :)

UBERMOUTH said...

4,000 plus 40,20,20,30=4,110.

James Higham said...

Why did you add 20 twice? The answer is hidden down in the right corner, under the picture.

CherryPie said...

That is one brain bender!!

Lord T said...

1000 + 40 = 1040
1040 + 1000 = 2040
2040 + 30 = 2070
2070 + 1000 = 3070
3070 + 20 = 3090
3090 + 1000 = 4090
4090 + 10 = 4100
many people when they carry the one in their heads add to the thousand column.

His Girl Friday said...

this one gets me every time. I always start with the wrong answer then have to work it again. I need to practice the mental math from the brain quiz thingy.

good to see everyone playing together well... ;)

Lord Nazh said...

It works that way because of the thought processes involved. Every other addition is a 1000 so the next total should be in a multiple of 1000 (ie. 5000)...

If you add the numbers in any other order, most people will get it right (although some won't because of the carry effect of the 1)

James Higham said...

It caught me out, even with the calculator in hand.

dearieme said...

You add the four thousands first. Remember your answer. Then you add the fragments. Then you add your two sums. Bingo!

James Higham said...

That's too intelligent, Dearieme - I've had to warn you about unwonted intelligence before. :)