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DCI Matte Black Powder Coated Metal Mathematics Blackboard Pop Quiz Clock, 11-1/2" Diameter
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- Each hour is marked by a simple math problem
- Matte black powder coated metal
- Requires 1 AA battery
- 11-1/2" Diameter
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CHOKING HAZARD -- Small parts. Not for children under 3 yrs.
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|Item Package Weight||1.15 pounds||1 pounds||1.6 pounds||1.3 pounds|
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Top Customer Reviews
***Update*** 4/1/2013 SO i did a little tinkering because I was bored on saturday and had nothing better to do... Turns out this whole thing is an undersized gear problem for the second hand... The gear is just way to small for the size and weight distribution of the second hand... So a simple fix for this, if your clock does what mine did, is to simple trim down the second hand to a size of abotu 3 inches from the base point tot he tip. Seems to be working just fine now. Still only going to give it two stars, as I had to take it apart to make it work
It's a great novelty item, everyone notices it and gets a kick out of it.
The circle that makes up the face is a thin piece, mounted on the square that houses the battery and mechanical parts behind it, so the circle will not sit flush on a wall. And the mount is in the middle of the top of that smaller square in back, making it tougher to find the right hanging point for mounting it.
Other than that, it works well, keeps pretty good time actually, only has to be adjusted a couple minutes each month.
On quiet nights though when I'm just working on my laptop and nothing is on the TV, you can hear the tick tick tick though, so if you're a person who doesn't like the ticking noise, you won't want this hanging anywhere that gets quiet.
Now, on to the one problem with it. The expression that is supposed to evaluate to 9, which is 3 * (pi - 0.14), actually evaluates to around 9.00477. Pi is irrational, so you can't express a natural number like 9 with an expression containing pi. I'm sure this has driven many other mathematicians insane, and I seem to be the first one to speak up about it.
Other than that slightly anal comment, its a great clock!
The only things keeping it from 5 stars:
* Somewhat loud, though 95% of the time I don't hear it. It's no louder than any other analog clock, but the distraction is up to how much you can tune that ticking sound out.
* One time it stopped working apparently due to the seconds hand getting stuck behind the minutes hand. I re-bent the seconds hand to be straighter, and then it started up again. No issues since
* Technically the 9 hand is incorrect since pi-.14 is not exactly 3. Since I work at a computer company with all engineers, some people actually point this out and "care". For what it's worth, if you're making a nerd clock, you have to realize there are nerd sensibilities around it.
Update: After a year, it has stopped working. The seconds hand gets stuck and won't move when the clock is upright. Changing batteries had no effect. Disappointed it only lasted a year as other wall clocks I have are going strong after 8 years. Knocked off a star for it, and getting another math clock as a replacement.
Most Recent Customer Reviews
I have a colleague who's a data scientist and I thought this would be a great gift for him. On second thought I'm sure the equations are way too simple but hey, it's a great gift... Read morePublished 1 month ago by Michael Lee
My son's math teacher is going to eat this up. He is a certainly a hard man to please, at least that's what the kids say . . .LOL!! He loves his math!! Read morePublished 2 months ago by rowles
Bought this for my brother because he is getting his PhD in math (gross ;-) ) It looks great on his wall and he really likes it. Read morePublished 2 months ago by Nicole Noble
Really really like this so far.. It was delivered in good shape and my smarty pants 7 year old absolutely loves it. So far no issues...Published 2 months ago by Stephwalt
This clock was designed for someone who likes mathematics. I am appreciate this gift to my self.Published 4 months ago by Edmond
Bought as a Christmas gift for my math/science teacher brother-in-law. He was very pleased.Published 4 months ago by Katie Mata