Arithmetic Question.

[Tilly2]

A friend has just sent this.
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?

THIS MUST BE DONE IN YOUR HEAD ONLY.
DO NOT USE PAPER AND PENCIL OR A CALCULATOR.
TRY IT.

I made it 5000 but that's incorrect. What's the trick?

[fiction-factory]

4100?

[fiction-factory]

Hope I'm right or I won't be able to show my face in school tomorrow. Hang on... what school?

[Sam1960]

4,100

[Patsy33]

4,000.? Take 1,000

[Prudie]

You're right until the very end (and I did it too). When you add 10 to the 4,090 in your head you say that's 5000 without thinking, brain playing tricks...

[Peter Pedant]

4100

1000 then 1040 then 2040 then 2070
then 3070 then 3090 then 4090
and finallllllly 4100

as FF - who is really good at hard a level qq
but being a sort of human trace function

Hi FF !

[fiction-factory]

Years ago I used to have something very similar on powerpoint as a Maths starter- worked every time.
I'll see if I can find it again on an old pendrive. Not that I'll need it for a while....

[fiction-factory]

Hi PP.
I was caught out recently by a video where someone was holding up cards with words on with letters in each word jumbled and some vowels missing- and I was really pleased when I decoded the full message instantly. But none of us noticed the hidden message on the back of each card as it was being picked up, or that the person holding up the card was wearing different shirt/sweater and tie/no tie every time

[Patsy33]

For goodness sake!....Can't believe I done that!..

[Tilly2]

Thanks for explaining, Prudie.

What a div I am. :-(

[THECORBYLOON]

I've seen this before, done it twice just now and got it wrong still!

[JJ109]

4100

[ToraToraTora]

it's extremly simple mental arithmetic, 4100, no trick. I assume because the last addition is 4090 + 10, the hard of thinking may possibly, if rat ar53d may try and make that 5000.

[THECORBYLOON]

I can assure you I am neither hard of thinking nor drunk. It is a well-known question and many folk get it wrong.

[Peter Pedant]

// I was caught out recently by a video where someone was holding up cards with words on with letters in each word jumbled and some vowels missing-//

this is used in emergency training t show that overconcentrating on one thing means you miss the big picture
this is central in unsorting chernobyl, three mile island and air crashes
( and medical emergencies altho it is now a bit dated)

we had playing volleyball whilst a gorilla swanned around the playing area - and even when you are TOLD that there is something going on you miss it - - changing backgrounds

[fiction-factory]

thanks PP - I'll have a look on youtube for my video and for your volleyball/gorilla one

[jno]

of course, if you're specifically counting passes there's no need to notice the gorilla

[Ken4155]

^
You sort of spoiled that by adding your comment, jno. :-( I obviously saw the gorilla because you mentioned it. I did not, however, see the colour change nor the team member leave the stage.

[jno]

I mentioned it because PP and FF already had, I was just supplying the link. But what I said also holds true for the curtain and the missing player: you might be missing the forest for the trees, but if your job is to count trees it won't matter.

But suppose if instead of counting passes you were just told "watch closely and write down everything that happens": then you might well see them all. In those terms, it's the instruction itself that's misleading: you're told to look for one thing and are then told you missed something else.

[marval]

I had seen it here.

https://www.theanswerbank.co.uk/Phrases-and-Sayings/Jokes/Question1126232.html