Math Is Fun Forum

You need to add the two fractions:

find the common denominator!

the process is the same as this process for adding fractions with 'ugly denominators':

3/23 + 7/57  is:

3 * 57  +  7 * 23
--------------------
        23 * 57

Does that help?

sounds like fun

@ espeon - I don't think you'll ever need to know about hex and bin and oct unless you take Computer Science courses at some point or want to study computers or electrical engineering or something closely related.

But if you want to learn them just for fun, I can try to explain more. just ask!

We use "base 10 numbers" because we use 10 digits: 0 to 9.
And when we count we start a new column after we get past 9 to 10, and start counting starting with 1 in that column again:
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ...

.. but thats not the only way it can be done! In Hex (hexadecimal) numbers we use 16 different digits, so when we count 7, 8, 9, ... we dont start another column and write 10. We use the letters A, B, C, D, E, F *as digits*. We only start a new column when we get to the digit F. The digits A to F have the values 10 to 15: A means 10, B means 11, and so on.
So counting in hex goes like this:
1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1A, 1B, 1C, 1D, 1E, 1F, 20, 21, ....

Notice that once we pass 'F', we have to start another column just as in regular decimal number counting.

Put your calculator into "hex mode" and try 1 + 9, 2 + 9, 3 + 9 and see what happens!

But: why would anyone do this? Well, its important for storing numbers inside computers. But thats a large topic.

Thanks to everyone for the nice welcome.

Actually I can't take any credit for coming up with the name... I just remembered it from an article about "integrals that can and cannot be done" from Wolfram Research, and the Polylogarithm function (PolyLog[n, z]) was one of the special functions that comes up with along with other integrals that have no elementary antiderivatives, like the functions erf(x), the log integral Li(x), and so on.

Here is a good definition: http://mathworld.wolfram.com/Polylogarithm.html

hi espeon, here is a simple introduction to the idea:

Consider multiplying 10 *by itself* twice: 10 x 10 = 100.

Or 3 times: 10 x 10 x 10 = 1000.

Or 4 times: 10 x 10 x 10 x 10 = 10000

Now, try to answer these questions:

"How many times do we multiply 10 by itself to get 100?"

"How many times do we multiply 10 by itself to get 1000?"

"How many times do we multiply 10 by itself to get 100000?"