Sunday, November 27, 2005

8th Grade Math

You Passed 8th Grade Math

Congratulations, you got 10/10 correct!


DaPi said...

# -7 is

* Irrational
* An integer
* A whole number
* A prime number

THAT'S A STRANGE QUESTION - 3 answers are correct!

Anonymous said...

So, is -7 an irrational or a prime? Can't figure that one out.

Jeff Hunter said...

THAT'S A STRANGE QUESTION - 3 answers are correct!
Well, no.

It's not a prime number because prime numbers are >= 2.

Whole number is a little more tricky. Some definitions of "whole number" define them as integers. On the other hand, some define them as "positive integers".

I'll admit, I chose integer as a best guess.

Pete_S said...

How old is 8th grade?

(btw I scored 10/10 but I think I may be too old!)

Jeff Hunter said...

How old is 8th grade?

gandolf989 said...

Apparently I would have gotten a B. I guessed that -7 was irrational. How can you have -7 apples?

Joel Garry said...
This comment has been removed by a blog administrator.
Bob B said...

-7 is an integer.

It is not irrational because it can be expressed as a ratio (e.g. -7/1). Rational and irrational numbers are distinct sets.

It is not a whole number because it is negative. Whole numbers are non-negative (they might be strictly positive, I'm a little fuzzy on that detail)

Is not a prime number. Prime numbers are a subset of the whole numbers. Since -7 is not a whole number, it is not a prime number.

Noons said...

Duh? Is there ANY integer number that cannot be expressed as a n/1 ratio?

Me theenks it's just an integer:
whole numbers must be positive. Primes must be positive. Irrational it ain't as it is not a ratio to start with.

Anonymous said...



You owe me seven apples, gandalf

DaPi said...

I'd say:

It's clearly rational - or would someone argue that numerators and denominators of rationals must be >=0 ?

It's a whole number - it has no fractional part.

It's an integer - for me: integer = whole number

It's a prime: its factors are 1 and -7 (if anyone argues against, saying that -1 and 7 are also factors, then 7 also fails to be prime with factors 1, 7, -1 and -7)

It's NOT a "natural number", which are the members of the set 1,2,3,4 . . . .

Very roughly, I'd consider -7 to have all the properties of 7, except that of being positive.
Any professional mathematician out there to put me straight?

Roger Snowden said...

Well, that was fun.


It's only irrational if you use it to calculate a baseline. :-)