Gifted Issues Discussion homepage Forums Learning Environments What grade level is this math problem?

This is not a big deal. Just curious.

A trapezoid has an area of 108 m2. Base 1 is 12 meters and base 2 is 15 meters. What is the height?

Sixth grade for my DD, though the curriculum has changed since then so not sure if that is still where it would be covered.

I'm going to go with 6th grade based on this:

http://www.corestandards.org/Math/Content/6/G/

CCSS puts it at 6th grade. Specifically:

CCSS.Math.Content.6.G.A.1
Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.

I agree that finding the area of a trapezoid seems to be 6th grade material by current standards, but what about the algebra needed for this one?

They do a lot of algebra before the subject called algebra.

For my DD, this type of problem was not unusual. I believe our math curriculum used this type of thinking fairly early on, though personally I don't think I would consider it to be learning algebra.
I actually have strong memories of the trapezoid/parallelogram/rhombus unit because it was a particularly good one, where DD worked in a small group where they were asked to derive the formulas, based on what they had learned about other shapes. She loved it, and still talks about it.

I'm not very mathy, I admit. I also have not been paying much attention to the math book! But to solve that problem, you solve for x, and it's not, you know, 2x =10. If that isn't algebra, what is it? (BTW, my DD could do it, but AFAIK she's still quite a ways away from "algebra," depending on what math course she tests into.)

I guess I don't know, but perhaps it's semantics, or maybe it's just me. Don't kids in early elementary often solve for unknowns using manipulatives and such? I know some people get excited that their second grader is doing algebra, I guess I sort of reserve that term for the actual course, while of course the concepts and groundwork may begin much earlier.

Well, I don't consider it algebra when my 1st grader answers x + 1 = 10, although it's intended to lay the groundwork, just as you say. I'd consider solving 108 = 1/2h(27) to be different, though you could do it by trial and error. However, my DD did it the traditional way. It doesn't really matter. I was just curious because I didn't expect this in her current course and wondered if it was a Common Core change.