In general - if you feel your child can handle a curriculum more challenging than their current grade level, you should consider having them 'skip' a grade to have access to the advanced material. The problem is that it gets much harder the older your child is; I'd guess it's exponentially difficult after 4th grade, unless you're supplementing their school experience with material at home. The main issue would be skipping too much important material - a year of science, or of history, for example. But if your child is older by the time you think they can handle more challenge at school, you can still play to their strengths - see if you can get them access to one or more advanced classes, instead of skipping the entire grade.
One of my children was ready to take Algebra for her 7th grade math course, but her middle school didn't offer that option. We were pretty sure she'd mastered the curriculum being offered, but weren't sure how to go about demonstrating that and getting the advanced class. We did a lot of research, and consulted with various administrators within HISD, and after a few months over the summer, got what she needed.
Getting credit for content mastery
We were encouraged to find, in the HISD guidelines (the documents are under the "School Guidelines" menu option on the left, or see section XII), that there was no longer a provision restricting pre-AP Algebra to 8th grade students; what we'd need to do, then was to demonstrate that our child had mastered the pre-requisite materials. Fortunately, that was not difficult; the middle school math curriculum in Texas is basically a tight spiral around learning decimals, fractions, percents, area, and volume. We spent a few weeks testing our child with the previously released TAKS exams, available by statute from the Texas Education Agency (if that link stops working, you can visit their home page and search for TAKS). Her performance on those was encouraging, so we contacted our school and then HISD administrators to find out what to do next. At HISD, we spoke with the Manager of the Gifted and Talented Department who was extremely helpful, and who in turn discussed the issue with the Manager of the Mathmatics Secondary Curriculum, Instruction, & Assessment. Thanks to those administrators, we became aware of an option known as Credit By Exam.
Credit By Exam (CBE) is a statutory mandate from the Texas Legislature, embodied in the Texas Education Code which is available online. We were particularly interested in Title 19 (Education), Part 2 (Texas Education Agency), Chapter 74 (Curriculum Requirements), Subchapter C (Other provisions), Rule 74.24 (Credit By Exam). This provision reads (rather drily) as follows:
(a) General provisions.
(1) A school district must provide at least three days between January 1 and
June 30 and three days between July 1 and December 31 annually when
examinations for acceleration for each primary school grade level and for
credit for secondary school academic subjects required under Texas Education
Code, §28.023, shall be administered in Grades 1-12. The days do not need to
be consecutive but must be designed to meet the needs of all students. The
dates must be publicized in the community.
(2) A school district shall not charge for an exam for acceleration for each
primary school grade level or for credit for secondary school academic
subjects. If a parent requests an alternative examination, the district may
administer and recognize results of a test purchased by the parent or student
from Texas Tech University or The University of Texas at Austin.
(3) A school district must have the approval of the district board of
trustees to develop its own tests or to purchase examinations that thoroughly
test the essential knowledge and skills in the applicable grade level or
subject area.
(4) A school district may allow a student to accelerate at a time other than
one required in paragraph (1) of this subsection by developing a cost-free
option approved by the district board of trustees that allows students to
demonstrate academic achievement or proficiency in a subject or grade level.
(c) Assessment for course credit in Grades 6-12.
(1) A student in any of Grades 6-12 must be given credit for an academic
subject in which he or she has had no prior instruction if the student scores
90% on a criterion-referenced test for the applicable course.
(2) If a student is given credit in a subject on the basis of an
examination, the school district must enter the examination score on the
student's transcript.
(3) In accordance with local school district policy, a student in any of
Grades 6-12 may be given credit for an academic subject in which he or she
had some prior instruction, if the student scores 70% on a
criterion-referenced test for the applicable course.
What this says is that if you've had prior instruction in a course, you are eligible to receive credit for that academic subject by taking a CBE exam and passing with a 70%. Crucial is the requirement that an administrator approve the application; all the CBE programs we saw had that as an application pre-requisite. Even better is the provision that you can receive credit, and a transcript grade, if you pass with 90% - even if you've not had any "prior instruction" in the subject. The latter is sometimes called "Exam for Acceleration". The middle school exams are available from Texas Tech and University of Texas at Austin; the 8th grade math is split into two semester tests, 8A and 8B. Students can also receive credit for High School courses through the HISD Virtual School (more on that later). We went with the Texas Tech program and were happy with it. They require a proctor, who was our middle school assistant principal; the materials are sent directly to the school, and the exam is given under normal conditions (each exam can take up to three hours). The completed work is sent back to Texas Tech, who typically takes about a week to respond with the grade.
Once that was done, our middle school had a last hurdle, which was to pass an assessment of our child's readiness for abstract concepts via the Iowa Algebra Aptitude Test. Once that was out of the way, she was ready to take the school's Algebra class in 7th grade.
Looking forward to High School
Texas, like any other state, has a set of required courses for each High School student to take. Among the requirements are two semester-long courses of life skills: Communication Applications (or, how to write a resumé and get a job!), and Health (more songs about sex and nutrition). Fortunately, these courses are offered online at the HISD Virtual School, and I'm strongly tempted to have my kids take them there so they can take other courses and/or electives during high school.
You might also consider having your HS student (or prospective student) attend courses at Rice University over the summer. The first alternative, Rice for HS students, is really quite expensive, but provides a "college experience". The second is a set of full day (8am - 3pm) classes for credit (or enrichment) at Rice Summer School.
If you're thinking of trying to help HISD tailor their curriculum to meet your student's needs, please let me know. Leave me a comment, and I'll follow up as best I'm able. Please also let me know about any errors or changes in the information above, if you're from HISD.