modulo converting

[Cogman]

Im sorry if I have spelled it wrong, the only place I have ever heard of it is in scholastics (knowledge bowl). Anyways scholastics is over, and I still have the question. How the heck do you convert numbers from one modulo to another? It is not like converting bin to hex. Or oct to bin. just as an example we had several questions that said something like convert 255 in module 9 to module 5. anyone help me understand these things?

no this is not homework, however none of my math classes (or teachers for that matter) can explane to me what the heck is going on.

 

[Matthew Daws]

Well, you could just convert to decimal and then convert back. I take it by "modulo" you mean "base", as it's quite a different thing!

For example, 255 in base 9 is 5+5*9+2*9*9 = 212 in decimal
= 125 + 3*25 + 2*5 + 2 = 1322 base 5

I take it that you know the algorithms for converting to and from decimal. Of course, you could just skip the decimal stage!

--Matt

 

[Cogman]

like I said in my post, but ill repeat it, IT IS NOT CONVERTING BASES. Just so yah know. I do know how to convert bases from one to another, but the bases that they are getting on questions dont make sence, like modulo (again, might not be how it is spelled) 4 to module three, with the module 4 number being 1234 would come out to like 2342, The number is bigger, but some have included number that are larger then the base, which to my understanding, should never happen. Ill see if I can get a example question for you.

 

[Shalmanese]

modulo N numbers can never be larger than N due to how they are conventionally defined. 4 modulo 3 would simply be 1.

 

[uart]

Originally posted by: Shalmanese
modulo N numbers can never be larger than N due to how they are conventionally defined. 4 modulo 3 would simply be 1.

Yep Cogman, I think you are confusing the terms of "modulo" and base". Your questions of converting from modulo 9 to modulo 5 dont really make much sense with the conventional mathematical definition or modulo. "Modulo 9" literally means the remainder after division by 9.

So your question "convert 255 in module 9 to module 5" translates to :

convert the remainder of 255 divided by 9 to to a remainder of a number (unspecified but possibly 255) divided by 5.

The problem is not the maths involved but rather that the question makes no sense to begin with.


BTW another common term for "base" is radix. Are you sure you have not consfused modulo with radix ?

Also note that in conversion of a number to another base (say to base r) that modulo-r arithemetic is central to the conversion process. So it is quite possible that you or someone else has somehow interchanged the two concepts.