#18. Mind teaser to exercise your frontal and parietal lobes

Let’s now exer­cise our frontal lobes (that deal with work­ing mem­o­ry and atten­tion, among oth­er things) and pari­etal lobes (visu­al interpretation). 


1. Count the num­ber of times the num­ber “6” appears below (you may need to scroll down).

2. Then, count the total of both “3“s and “7“s, try­ing to add the total num­ber of both as you see either (this is, don’t just count all the “3“s, and then the “7“s, but both at the same time)

1234467889974674657865876576576 3576573625432657346578436578342 2732188582735827456724687343828 7672878682768723682376783768267 2647648823178346432764876774653 7436574386581483627868653873465


The most impor­tant thing here is not to get the right answer, but to try. This type of exer­cise has been used by the mil­i­tary to improve atten­tion for decades (now there are more advanced, com­put­er-based, tools, but this keeps being fun).

Next brain teas­er in Sharp­Brains’ top 25 series:


  1. Neethster on October 1, 2008 at 8:27

    I got 33 and 59.

    • Nick on May 17, 2016 at 6:20

      i love it

      • Nick on May 17, 2016 at 6:24

        i don’t know if you have a radio

  2. John on October 7, 2008 at 2:46

    If you nor­mal­ly read left to right, try count­ing find­ing the num­bers scan­ning right to left… it will increase the accu­ra­cy. And, scan­ning from bot­tom to top (if you nor­mal­ly read top to bot­tom) will help you not skip lines.

  3. Birgi on November 25, 2008 at 1:15

    first I got 34 6es then I was count again and I got
    33 of 6es.
    I was got only
    27 of 3s and 7s at the same time.

  4. red on December 18, 2008 at 6:45


  5. Kayla on January 8, 2009 at 3:15

    I got exact­ly 33 and 59 sooo excit­ed woohoo!!

  6. anne on February 1, 2009 at 1:18

    19 & 55

  7. anne on February 1, 2009 at 1:25

    19 & 55
    2nd try:
    33 & 55

  8. ana on February 19, 2009 at 4:09

    33 6s woo hoo!

    I read the instruc­tions that we had to count the 3s and 7s indi­vid­u­al­ly but at the same time so to keep track I count­ed the 3s using num­bers and the 7s using the alpha­bet… and came out with 23 3s and 36 7s = 59 total I’m shocked !!!

  9. DAVIS on February 27, 2009 at 6:53

    I got 33/ 3s.AND I ADDED AS I WENT THRU THE 3S AND 7S CAME UP W/ 332

  10. Susie on February 28, 2009 at 6:40

    Well, if I had been a sol­dier I would have missed one of the ene­mies named “3” and would have mis­tak­en one of my own peo­ple as a “3” or a “7.” Not good in battle!

    I got 32 6’s. And I got 60 7&3’s. I tried it two dif­fer­ent ways. First I tried visu­al­ly match­ing 7’s and 3’s togeth­er to make 10’s so it would be eas­i­er to add. I found myself mark­ing 7’s with my fin­ger on the screen, though, since they were not even­ly matched. Then I tried a dif­fer­ent strat­e­gy which could tech­ni­cal­ly be cheat­ing, I sup­pose. As I came to a 3, I would name them in order such as 3–1, 3–2, 3–3, while also nam­ing the 7’s aloud as I came to them, 7–1, 7–2, …by the end I was at 3–24 and 7–36. I then men­tal­ly added 24 + 36 = 60.
    So, I did them as I went, but sep­a­rate­ly, as well.

  11. Are D on March 11, 2009 at 8:27

    Nice exer­cise! But I’m a bit puz­zled at some­thing: In the text at the top of this page you say this task exer­cis­es the Frontal and Pari­etal lobe, and that the Pari­etal lobe deals with visu­al inter­pre­ta­tion. I thought the Occip­i­tal lobe was the pri­ma­ry visu­al inter­pre­ta­tion cen­tre, and that the Pari­etal lobe main­ly deals with sen­so­ry infor­ma­tion. How come this isn’t an exer­cise main­ly for the Frontal and the Occip­i­tal lobe?

  12. hides on March 11, 2009 at 9:03

    yeah, 33=6’s and 59=3’s + 7’s

  13. Willow on April 28, 2009 at 5:14

    I have a closed head injury and find the exer­cis­es a bit of a men­tal work­out. Since I found your site I try and do a few exer­cis­es every day.

  14. lizzy on May 2, 2009 at 10:49

    6 = 29
    3 & 7 = 59

  15. Neeti on October 26, 2009 at 7:46

    33 and 59 !

  16. Abhishek on November 7, 2009 at 3:52

    33 and 59

  17. Saeed on November 12, 2009 at 7:56

    I got 32 and 58 not bad one way!

  18. Nick on May 17, 2016 at 6:23

    oh yes

  19. Satya on May 29, 2020 at 7:51

    This is intense!

About SharpBrains

SHARPBRAINS is an independent think-tank and consulting firm providing services at the frontier of applied neuroscience, health, leadership and innovation.
SHARPBRAINS es un think-tank y consultoría independiente proporcionando servicios para la neurociencia aplicada, salud, liderazgo e innovación.

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