I remember taking in Algebra, while in High School, something called "equations to the/of 3rd degree" which took imaginary and real numbers to produce two answers...

That was in a past life. :-)

Today's curricula are watered down at best. (Don't get me started....) While we teach n-th degree equations in Algebra 1, we don't address those with imaginary roots. So we DO equations with two or more answers. But we leave out the possibility of non-real answers, to be covered in subsequent courses.

In what grade do you cover "group theory"? (teoría de conjunto) I do not really know if that's the term in English. :p

I think it's a topic in "Discrete Math", which is not a required course of non-math majors. (If it's what I think you're referring to....)

Probably. As it has to do with computers and logic. That's where the "truth table" and others come from.

Yup - that's "Discrete". The truth tables for "logic" are taught in Geometry (I think), but anything more complex is "Discrete".

Teoría de conjuntos es "set theory". "Group theory" es teoría de grupos; un grupo consiste en un conjunto C y una function * que satisfacen cuatro axiomas.

1. Cerrado: si c1 y c2 están en C, (c1 * c2) también está en C.
2. Existe un elemento de identidad I: es decir que (c1 * I) = c1 para cualquier c1 en C.
3. * puede invertirse: para cualquier c1 en C existe un c2 tal que (c1 * c2) = I.
4. * es asociativa: (c1 * c2) * c3 = c1 * (c2 * c3).

Sí, "set theory". Recuerdo haber escuchado eso antes, acá en EEUU.

Excellent! Thanks for all of that great vocabulary!!

Another question for you all.

I team teach an Algebra class for English-as-a-Second-Language students. I am the "math specialist" and the other teacher is the "ESL specialist". Most of our students are native Spanish speakers. The other teacher knows some Spanish, although I don't remember where/how she learned it. She is not actively studying it.

Recently, I was talking about writing units on measurements that are proportional. For example, in English, if a speed is given in "meters per second", it is written as "m/s". Some of the kids were asking me about "per". I think that at some point in time, I heard something in a similar context that used "por", like if something happened once a day, it would be said "una vez por día". Is that correct or incorrect?

Anyway, I said something to some of the students about "per" in English being like "por" in Spanish. My team teacher jumped in and said, "well, it's like 'cada'. 'Each'." I suppose that makes logical sense to me, but for some reason it seems incorrect.....

So what is the correct way to give a proportional unit?

Thanks!!