Can you do this with out a calculator?

  1. Akari_32 Fishlore Legend Member

    A friend of mine posted this on FaceBook. Try it! =D I'll post the rest of it (I cropped out the answer) after a few people post what answers they get ;)


    If you know it, don't spoil it!
  2. Borisbbadd Guest

  3. Akari_32 Fishlore Legend Member

    Now do it with a calculator, and see what happens ;D (But don't post it!)
  4. Borisbbadd Guest

    I just did.....ooooops !!!
  5. Akari_32 Fishlore Legend Member

    I know, right?? I just tried it a couple different ways, like adding up all the 1000's, then adding the smaller numbers, but it still does it o_O
  6. I keep fish Well Known Member Member

  7. Akari_32 Fishlore Legend Member

    What kinda math are you doing? o_O
  8. I keep fish Well Known Member Member

    idk The stupid kind I was just guessing

  9. Akari_32 Fishlore Legend Member

    Lol when you do it in your head its supposed to come out to 5000 XD
  10. I keep fish Well Known Member Member

    I did do it in my head
  11. Akari_32 Fishlore Legend Member

  12. angelfish220 Well Known Member Member

    why is it hard? I got the same as post 8
  13. ryanr Moderator Moderator Member

  14. Akari_32 Fishlore Legend Member

    It comes out to two different things depending on how you do it. Its creepy! I'll post the rest of the pic now lol
  15. Akari_32 Fishlore Legend Member

    Here we go lol

  16. kinezumi89 Fishlore VIP Member a soon to be engineer, I feel like a failure XD
  17. Akari_32 Fishlore Legend Member

    Isn't it weird?? o_O
  18. TmacD Member Member

    I nailed it the first time. I added all the thousands then the tens. My mind works that way though, I had to add time all the time when I worked in t.v.:;dete
  19. ryanr Moderator Moderator Member

    Take 1000 and add 40. = 1,040
    Add 1000. = 2,040
    Add 30 = 2,070
    and then add 1000. = 3,070
    Add 20. = 3,090
    Add 1000 = 4,090
    and then add 10. = 4,100

    The 'trick' is in the way you do things in your head, in words, not in numbers.
    Most people tend to break the numbers down, for easier recall, such that:

    Take 1000 and add 40. = 1,040 => Ten Forty (in your head)
    Add 1000. = 2,040 => Twenty Forty
    Add 30 = 2,070 => Twenty Seventy
    and then add 1000. = 3,070 => Thirty Seventy
    Add 20. = 3,090 => Thirty Ninety
    Add 1000 = 4,090 => Forty Ninety
    and then add 10. = 4,100 => Brain 'complains'. The last numbers in your head were Forty Ninety, +10 becomes Forty One Hundred = The brain automatically ticks over and resets the count to 0, and increases to Fifty in your head, because of the break-down to 'simpler' numbers, the brain fails to recognise Forty One Hundred as a real number.

    For those that added it in full, i.e. One Thousand and Forty + ....., tend to get the correct answer of 4,100
  20. Akari_32 Fishlore Legend Member

    I tried that, too, but I guess I didn't do it right (but I'm not a math whiz. My TI-89 is my best friend LOL)