First, next Friday I am speaking at a special conference for A-level students on science and pseudoscience. If you are a teacher or a student or even a normal person, and interested in coming along, the details are here.

Second, here is the Friday puzzle! A simple one this week, can you make the following equation correct by moving just one number…..

62 – 63 = 1

As ever, please do NOT post your answer, but do say if you think you have solved it and how long it took. Solution on Monday!

68 comments

  1. Wow! I managed to get this really quickly. It’ll probably just serve to bring me down to earth harder next friday

  2. Got a solution straight away but it is very liberal with what you could call a number (when it comes to moving one number). Is that the correct solution?

    1. I reckon we’re on the same track, but I’ll be disappointed if that’s actually the answer! I suspect it’s not.

    2. I was wrong. I was thinking if you move the top part of the equals sign it becomes 62 = 63 – 1 this is wrong. You can do it by moving one number which is after all what the puzzle asks for.

      I hope this doesn’t break the answer rule but I can see I’m not the only one who found this incorrect solution, the right one just hit me then when I checked to see if anyone had corrected me.

  3. I’m missing something….is the question correct?….. Is it really to “name” or is it to read “make” the equation correct by moving just one number? I’m clueless right now….have to retry later maybe after some sleep….it’s about 2 am my time and not gone to bed yet…..will try later today….

    1. Sorry, class can be singular or plural depending on the context. Just like staff, crew, group, etc.
      ‘The group is in the classroom. The group are all happy.’
      ‘The crew are revolting, sir.’

    2. Rob, this usage is very rare in American English, so I’m guessing that’s what The Pick Man is familiar with. On this side of the pond, we almost uniformly treat group nouns as singular — “the team has taken the field”, “the media is in an uproar”, etc. The phrase above might best be re-worded in AmE as “The students are all beaming . . .”

    3. Yes, I had heard that it was rare in American English. I guessed that might be the case – however, the Pick Man’s blog (which is very good, btw) implies that he is British, or at least living in Wales.
      Sorry to be pedantic about his pedantry – pedants of the world, unite! You have nothing to lose but your apostrophes, collective nouns and mistranslations… he he he. 🙂

  4. Powerful puzzle this week, professor!

    As well as by moving one digit, I can also solve it by moving one (non-digit) pen stroke. 🙂

  5. This is a difficult one. The only solution I can think off, doesn’t comply with what is been asking 😦

    (I hope it is not one of the famous late corrections after)

    1. Okay, I got it… but only because of two comments that combined, are deadly to any puzzle solver. I’m not sure I’m happy. For one, I don’t have the time, for another, I probably would have said, “why didn’t I thought on that?”, surprised and amazed, Monday… this way, I feel I cheated. Definitely, I should stop from reading comments before solving the puzzles. 😦

  6. I can do it by moving just one number, but I’d need to fiddle with the non-number parts a bit, and I’m afraid that would constitute cheating.

  7. I’ve seen this one before and I don’t think it’s easy at all. It’s not the kind of thing they’d allow on Countdown!

  8. I have several answers for this puzzle, none of which seem so obvious that they would be the answer Richard is looking for and some responders are so certain about, it being the right one.

    But given the loose bounds of the text, I have at least 3 solutions which are in certain interpretations correct…

    I shall be smug about it on monday.

  9. There are actually 2 answers, both wich are correct given the way the question is posed.

    Now bite my nails till Monday to see wich one your after.

  10. Hmm…I got stuck on the wording, I think saying to move one number is misleading…since their are only 3 numbers, but 5 digits to work with and it can’t be done using the 3 numbers you’ve been given.

    1. Yep, by ‘numbers’, he means ‘digits’. I _think_ that’s the only bit of ambiguity in this one

  11. if you are not sure if it’s correct then you don’t have the correct answer. once you get the correct answer then you won’t question the correctness of it xD

  12. Good one. Took me, on and off, bout 20mins.
    So glad I didn’t scroll beyond first few comments before solving: some of you guys just can’t help yourselves can you?
    Comments on here help thickies like me know that the puzzle can be solved and maybe iron out some ambiguity: It is very frustrating to read a BIG clue when all your seeking is assurance.
    Idea: Have a ‘suppress spoilers/clues’ button on comments
    or,
    open up Monday’s answer + comments page on Friday with Richard updating it on Monday with his answer. Then all the smart arses can post there instead.

    OMG I really need to get a life lol.

  13. Read it and tried for a bit yesterday, slept on it, still can’t figure it out.
    I’ve read all the comments, even watched that boring cartoon thing, still nothing.
    I feel dumb as a door :/

    I’ve run through all permutations of digit replacements, no equation turns out true.

    I had the match-stick solution after a minute on friday, but the digit solution is just long gone for me.

    I’m frustrated 😦

  14. Just remember that you can not apply the rules for working with equations to this problem because it is not an equation.

  15. Took several minutes of fairly mechanically trundling through the possible variations. In retrospect, should have leapt out at me….On another day, it may have done.

Leave a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.