I Passed 8th Grade Math!

10/10

Though I nearly dropped the ball because I forgot whether "the whole numbers" were the integers or the natural numbers.

90%; messed up on the 2,2,3,4,5 problem. What's the *&^%$#@ right answer and why?

the answer is "mode", meaning the most common number/score listed.

How does (.4 < x < 1/2) make 45% a candidate for x? Where do the percentages come in from??

Beware of HTML entities.

How does (.4 < x %lt; 1/2) make '45%' a candidate for x? Where do the percentages come in from?

that's because .4 = 40% and 1/2 = 50%, so the answer is 45%.

I got 10/10, but is that really 8th grade?! I'd think it is a mix of 3rd, 4th and 5th grade. So, is that why US education is lagging so far behind the rest of the world?

that's because .4 = 40% and 1/2 = 50%

Duh, but that's not defined anywhere (i.e. 1.0 = 100%), so the percentages don't make sense.

My youngest just is in grade 11 (Canada) and this seems about right for grade 8) Got 10/10 but i had to guess at the mode thing, however none of the other opitions seemed to make sense

I got 10/10, but the question with the percents is bad. percents are ratios. If you just say 0.4 to me how do I know you don't mean .4%? or 1/2 %. I got the answer right because I could guess what was wanted, but if these are the kind of questions in a real test, they are so much noise in reality.

My 6th grader just got 10 of 10. Great. Now he thinks he doesn't need to go to school on Monday...

I'm not sure what the confusion is on the ".4 < 45% < 1/2" question.

40% = 40/100 = 2/5 = .4
45% = 45/100 = 9/20 = .45
50% = 50/100 = 1/2 = .5

These are quivilant ways of representing the same numeric value. The question, as presented, is in fact a very good question because it requires this understanding of the relationship between fractions, decimals, and percentages.

Oops, not sure where my < disappeared to.

Well, I got 10/10. Given that I'm a maths undergrad (albeit a tipsy one) anything else would have been a leeetle worrying...

9 of 10 missed one of the definitional questions the first time. mode / whole-natural? / percentage are obviously problems even for many who read this blog. I suspect that these three questions have more to do with how well you accept rules than how well you can do math.

Its crap. Yes I got ten out of ten but the notation sucks. Is it 41 divided by 3? Is it 4 x 1/3? Is it 4 + 1/3? There is an implied expertise here, and totally inadequate explicitness with regards to orders of operation. Not good enough for an elementary school text, yet willing to evaluate capability, to assign a score. And no email link providing a feedback loop. Who wrote that shit? Not a mathematician.

Well, I'm a math undergrad, too, and I got 10/10. However, question 2 is wrong: -7 is simultaneously an integer and a prime, as it's only divisible by its associates, 7 and -7, and by units, 1 and -1 (yes, I'm an abstract algebra geek).

I agree with Coturnix: it's surprising that this is considered 8th grade math. When I was tested in 7th grade to see if I could be exempted from math classes, I had to solve considerably more difficult questions, such as a horribly intricate linear equation in one variable, and a fairly intricate system of two linear equations in two variables.

Alon Levy writes:

However, question 2 is wrong: -7 is simultaneously an integer and a prime, as it's only divisible by its associates, 7 and -7, and by units, 1 and -1 (yes, I'm an abstract algebra geek).

According to The Prime Pages, a prime number is defined as -

An integer greater than one is called a prime number if its only positive divisors (factors) are one and itself.

Wikipedia and Mathworld (and several other websites I checked) also agree that a prime number must be a positive integer.

But I'm not an expert, and so there might well be some odd abstract mathematics that treats negetive primes as well. I don't think 8th graders should be faulted for that though.

All right I admit I got only 8 out of 10. But I took 8th grade math 56 years ago! I got an A then, but hated it as well, alway have been a right-brain person. I am going back to reading my "Freakonomics" book, thank you.

Wikipedia says:

In the context of ring theory, a branch of abstract algebra, the term "prime element" has a specific meaning. Here, a ring element a is defined to be prime if whenever a divides bc for ring elements b and c, then a divides at least one of b or c. With this meaning, the additive inverse of any prime number is also prime. In other words, when considering the set of integers as a ring, − 7 is a prime element. Without further specification, however, "prime number" always means a positive integer prime.

A cook! I found a cook!
Number 7 has two correct responses (second and third).

Sadly, I think that many of my incoming freshmen could not pass 8th grade math. :(

10 for 10

off topic, but after reading your post on lablit I read the excellent "Brazzaville Beach" - highly recommended. A newly published lablit-type novel getting excellent reviews is "Intuition" by Allegra Goodman, dealing with cancer researchers.

wow, i am impressed that so many people want to take a math test, and on a saturday evening and sunday morning, no less. why aren't you all out on hot dates or sleeping in?

ah, but of course, this is cuz PZ linked to this math test, so he's sharing his smart peeps with me.

to answer a few comments; i was always under the impression that a prime number could only be greater than one, too. but the night prior, i almost pickled the particular neuron that contains that memory, so it took nearly a minute of deep thought to recall.

and thanks for the LabLit recommendation, Matt. i will try to get a copy of that book (along with the highly recommended Brazzaville Beach). if it's new enough, i might be able to convince a publisher to send it to me, free-of-charge, so i can review it here. alas, i already have three books i am reading/reviewing right now, and even though they are spendid books, i am getting a little bit behind on my reading schedule. but shhhh! don't tell the publishers that, or i might have to start buying my own books again, and i currently can't afford my biblophilia.

Late to the party, but I got 10/10. It may not be 8th grade math, but whatever it is, it was fun. I haven't had a math class in more than 35 years (well I did have a stats class in college which is where I learned about median, mode, and average).

Well, I passed with ten out of ten...but I probably lose a point for not knowing what age 8th-grade corresponds to 'over the pond' (sorry, I'm a Brit...don't hold it against me). I dread to think how many of my friends would get less than seven marks on this test. But then, I work in a library, and every day deal with university-level students who can't fill in a library joining form correctly....that's a library joining form with no maths questions, BTW. [/sigh]

VelcroCityTouristBoard

Wikipedia says:

In the context of ring theory, a branch of abstract algebra, the term "prime element" has a specific meaning. Here, a ring element a is defined to be prime if whenever a divides bc for ring elements b and c, then a divides at least one of b or c. With this meaning, the additive inverse of any prime number is also prime. In other words, when considering the set of integers as a ring, â 7 is a prime element. Without further specification, however, "prime number" always means a positive integer prime.

Alon Levy, I think you are using a gun to kill a mosquito ;)