# Sample Math Problem from OECD International HS test **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [December 3, 2013, 3:19pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375 "2013-12-03T15:19:49Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![pancakes3](https://avatars.discourse-cdn.com/v4/letter/p/ba9def/32.png) [@pancakes3](https://boards.straightdope.com/u/pancakes3)\ **Post date:** [December 3, 2013, 3:19pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/1 "2013-12-03T15:19:49Z")
Couldn’t decide whether to put this in the MPSIMS thread. This is a sample math problem from one of those “Chinese students are outstripping American ones in standardized testing…” tests. It was a nifty little problem. I got the right answer but felt I spent way too long on it (4 mins ish?) than what would constitute a “good” score. > **[Here's A Question About A Revolving Door That The Smartest Math Students In...](https://www.businessinsider.com/pisa-revolving-door-question-2013-12)** Just thought I’d mundanely and pointlessly share while posing a factual question. ---
**Author:** ![The\_Niply\_Elder](https://avatars.discourse-cdn.com/v4/letter/t/8e8cbc/32.png) [@The\_Niply\_Elder](https://boards.straightdope.com/u/The_Niply_Elder)\ **Post date:** [December 3, 2013, 3:31pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/2 "2013-12-03T15:31:14Z")
Hm that took me about ten seconds to figure out. I think though that the prowess of Asian mathematics skills are greatly exaggerated, from my own anecdotal experience. ---
**Author:** ![newcomer](https://avatars.discourse-cdn.com/v4/letter/n/e5b9ba/32.png) [@newcomer](https://boards.straightdope.com/u/newcomer)\ **Post date:** [December 3, 2013, 3:44pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/3 "2013-12-03T15:44:48Z")
In this case, math is very simple - the question is understanding the problem which is more engineering than math. Math that I remember from HS was more about understanding Cantor’s Theorem than problem solving. This is what we used to do in HS… you get an equation and you have to work it to prove the equation… something like this… [Trigonometrija - dokaz ili pojednostavni izraz - YouTube](http://www.youtube.com/watch?v=YZwL1-tzk3c) Note: video is in Croatian. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [December 3, 2013, 3:58pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/4 "2013-12-03T15:58:43Z")
Since I’m not seeing an actual question in the OP, let’s move this to MPSIMS. Colibri General Questions Moderator ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 3, 2013, 4:20pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/5 "2013-12-03T16:20:20Z")
It took me longer to load the page than to figure out the problem (aside: I really hate web pages that jump around while they’re loading). And then I had to read it over again to be sure there wasn’t some trick I was overlooking. ---
**Author:** ![Terr](https://avatars.discourse-cdn.com/v4/letter/t/839c29/32.png) [@Terr](https://boards.straightdope.com/u/Terr)\ **Post date:** [December 3, 2013, 4:24pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/6 "2013-12-03T16:24:41Z")
> [@The\_Niply\_Elder](#): > > Hm that took me about ten seconds to figure out. I think though that the prowess of Asian mathematics skills are greatly exaggerated, from my own anecdotal experience. I know, the answer is pretty obvious - 10 seconds is about right. Why is this considered a difficult question? ---
**Author:** ![QuickSilver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quicksilver/32/7832_2.png) [@QuickSilver](https://boards.straightdope.com/u/QuickSilver)\ **Post date:** [December 3, 2013, 4:28pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/7 "2013-12-03T16:28:41Z")
Took me less than half a minute, including trying to find a scrap piece of paper to write out the solution for full marks. 🙂 I’ve got two kids in hs. One freshman, one senior. Just for fun, I’m going to see how quickly they can solve it this evening. ---
**Author:** ![shijinn](https://avatars.discourse-cdn.com/v4/letter/s/cc9497/32.png) [@shijinn](https://boards.straightdope.com/u/shijinn)\ **Post date:** [December 3, 2013, 4:53pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/8 "2013-12-03T16:53:23Z")
i think you learn circumference in primary school, so you don’t even need a teenager to solve that. anyway, is this OECD International HS test taken by American students? if not, how do they compare the rankings? ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [December 3, 2013, 4:55pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/9 "2013-12-03T16:55:26Z")
They even show the door in the right position to visualize what’s needed. I’m an engineer, took like 10 seconds. ---
**Author:** ![drewtwo99](https://avatars.discourse-cdn.com/v4/letter/d/d07c76/32.png) [@drewtwo99](https://boards.straightdope.com/u/drewtwo99)\ **Post date:** [December 3, 2013, 5:10pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/10 "2013-12-03T17:10:15Z")
> [@Chronos](#): > > It took me longer to load the page than to figure out the problem (aside: I really hate web pages that jump around while they’re loading). And then I had to read it over again to be sure there wasn’t some trick I was overlooking. This is where I fell, except I wasn’t very sure of my answer for some reason. I was like ‘well it really seems obvious the answer is \_\_\_\_\_, but… hmmm maybe there’s something I’m missing.’ ---
**Author:** ![pancakes3](https://avatars.discourse-cdn.com/v4/letter/p/ba9def/32.png) [@pancakes3](https://boards.straightdope.com/u/pancakes3)\ **Post date:** [December 3, 2013, 5:12pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/11 "2013-12-03T17:12:47Z")
> [@shijinn](#): > > anyway, is this OECD International HS test taken by American students? if not, how do they compare the rankings? Here are some rankings > **[Here's The New Ranking Of Top Countries In Reading, Science, And Math](https://www.businessinsider.com/pisa-rankings-2013-12)** > > A brand new list! > [@Snarky\_Kong](#): > > They even show the door in the right position to visualize what’s needed. That was the “duh” moment for me. ---
**Author:** ![DMark](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@DMark](https://boards.straightdope.com/u/DMark)\ **Post date:** [December 3, 2013, 5:22pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/12 "2013-12-03T17:22:36Z")
Well, I didn’t use any real math formula, but just sort of guessed using the 200 CM factor, but I would have at least mentioned the extra bit needed to keep it sealed. I might have scored the points - but most likely the only points in the entire math section for me. ---
**Author:** ![Typo\_Knig](https://avatars.discourse-cdn.com/v4/letter/t/cdc98d/32.png) [@Typo\_Knig](https://boards.straightdope.com/u/Typo_Knig)\ **Post date:** [December 3, 2013, 6:02pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/13 "2013-12-03T18:02:36Z")
Is their answer off by a factor of 2? The diagram shows the arc subtends a 120 degree angle. A circle is 360 degrees and 2_Pi radians in angle. Therefore Pi radians is 180 degrees, Pi/3 radians is 60 degrees, and 2_Pi/3 radians is 120 degrees. The arc subtends a 120 degree = 2_Pi/3 radian angle. The definition of angle is radians is arc length over radius. So the angle T = S/R where S is the (unknown) arc length, R = radius = 100 cm, and angle T is 2_Pi/3 radians (= 120 degrees). So the arc length (S) is R_T or 2_Pi/3 times 100 cm or 200 cm \* Pi/3. Their answer is 100 cm \* Pi/3. Or did I do something wrong again? ---
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [December 3, 2013, 6:04pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/14 "2013-12-03T18:04:50Z")
> [@Snarky\_Kong](#): > > They even show the door in the right position to visualize what’s needed. > > I’m an engineer, took like 10 seconds. Took me longer than that, but I’ve been taught to distrust diagrams in word problems. I had to convince myself that what looked like 50% was really 50%. In my defense, I haven’t done a geometry proof in 33 years. If I’d thought to have kids to help with their homework, I’d be better at this kind of stuff. I do agree that this wasn’t particularly difficult. When I first looked at the problem, i was expecting to have to calculate the length of a chord intersecting the circle and then I would have been sunk. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [December 3, 2013, 6:08pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/15 "2013-12-03T18:08:31Z")
**Typo Knig** , you’re supposed to find the length of **each opening**. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [December 3, 2013, 6:09pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/16 "2013-12-03T18:09:40Z")
As soon as I realized that each door opening was 1/6 of the circumference, the answer was obvious. ---
**Author:** ![shijinn](https://avatars.discourse-cdn.com/v4/letter/s/cc9497/32.png) [@shijinn](https://boards.straightdope.com/u/shijinn)\ **Post date:** [December 3, 2013, 6:20pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/17 "2013-12-03T18:20:45Z")
> [@pancakes3](#): > > Here are some rankings > > [Rankings of Countries in Math and Science - Business Insider](http://www.businessinsider.com/pisa-rankings-2013-12) … if American students are also taking the same tests, then i must have misunderstood the point in the OP’s link. i had assumed it was “the Asian students weren’t as smart as they claim, the tests were simply easy.” btw what was your factual question, **pancakes3**? ---
**Author:** ![Typo\_Knig](https://avatars.discourse-cdn.com/v4/letter/t/cdc98d/32.png) [@Typo\_Knig](https://boards.straightdope.com/u/Typo_Knig)\ **Post date:** [December 3, 2013, 6:20pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/18 "2013-12-03T18:20:52Z")
> [@Thudlow\_Boink](#): > > **Typo Knig** , you’re supposed to find the length of **each opening**. D’Oh! I thought _they_ would not make such a basic mistake. That’s my speciality. ☹ ---
**Author:** ![Blaster\_Master](https://avatars.discourse-cdn.com/v4/letter/b/cab0a1/32.png) [@Blaster\_Master](https://boards.straightdope.com/u/Blaster_Master)\ **Post date:** [December 3, 2013, 6:43pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/19 "2013-12-03T18:43:03Z")
Based on the article, I was worried that I over-simplified the problem, but it was as simple as I thought and my intuitive answer was correct. I think it would have been more difficult without a diagram, but then it’s only difficult because of the setup. IMO, this is something that anyone with geometry ought to be able to answer fairly easily, and likely many people with less education, as long as they know the formula for the circumference of a circle ought to be able to get it right. Frankly, considering that geometry is a required subject, if this is one of the hardest questions, it sounds like this is a fair test for a high school education. ---
**Author:** ![AdmiralQ](https://avatars.discourse-cdn.com/v4/letter/a/8797f3/32.png) [@AdmiralQ](https://boards.straightdope.com/u/AdmiralQ)\ **Post date:** [December 3, 2013, 6:59pm UTC](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375/20 "2013-12-03T18:59:48Z")
If that’s one of the most difficult questions, I shudder to think what the easy ones are like. Possibly: Solve for x: 1 + 1 = x If the vast majority of high school students in America can’t solve the linked problem, then we might as well close the doors and shut off the lights on the country, since we are doomed to become a second or third rate society. [Next page](https://boards.straightdope.com/t/sample-math-problem-from-oecd-international-hs-test/675375.md?page=2)