# Ummm… What time is it?

Can you find the typo?!

As I troll through the web, I often wander through sites that have some pretty humorous math related content.  When I find some I’d like to share, I’ll add them to this page.  I will try to keep whatever I post to the PG level at most.  (Yes there is risqué math, who knew!?)

NOTE: I do not own nor imply ownership of any images I find on the web.  Whenever possible, I will provide info on the rightful owner.  If you discover a picture/link which I have incorrectly attributed, please let me know!

This picture has been going around Facebook for a while… but it has a typo!! Do you see it?

## 11 thoughts on “Ummm… What time is it?”

1. sasha aka justin says:

where 5 o’clock is supposed to be is wrong its supposed to be square root of 9 plus square root of 9 minus 9 divided by 9. if that made sense

• Congrat Sasha! (Hi BTW… I miss you guys) You are right that it is the 5 o’clock position… and I think if you were going for
$\sqrt{9}+\sqrt{9}-\frac{9}{9}$
then yes, that is an appropriate answer… but there is an easier way to fix the currently written clock…

• sasha aka justin says:

have a normal clock and i miss u guys too it was best summer yet for most part

• Ah, I see it. The factorial has to be put outside the radical.

Fun clock and fun challenge, by the way. Thanks for posting it.

• Chiaroscuro says:

Indeed, you can work off the principle of the 7 to keep it within three 9’s, just changing the last plus to a minus.

Now, not a typo but a subtler thing is that 1 has been yielded with only two 9s. I can be done in three, though, in several ways. 🙂

• I just smiled as I thought of this formula for getting 1 out of exactly three 9’s:

$9^{9 - 9}$

2. Reblogged this on nebusresearch and commented:
Math 4 Most put up a lovely little challenge here, to find a typo in a novelty clock face. As usual for this sort of novelty clock face the various expressions come out to the familiar old 1, 2, 3, et cetera up through 12; so, can you spot one (or more than one) that doesn’t come out right?

Every couple years someone in my family buys me one of the mathematical-puzzle calendars, where there’s a bit of arithmetic to work out for each day. (For example, something for today might ask the square root of 196, although dressed up to be more interesting.) It’s good mental practice working through it, the equivalent of doing the daily Jumble word puzzle or a Sudoku problem. I admit I’m more inclined to the Jumble since I like many of the wrong words that come up in trying to unscramble ‘Object’ and ‘Recipe’. (Those are the words causing more more trouble than any in the common Jumble vocabulary.)

3. Using three 9s, you can do five by 9-sqrt(9)-.9bar. One with three 9s can be as simple as 9-9+.9bar.