On the Internet there is a plethora of practice material for the math portion (and science, reading, etc.) of the TAKS test. The Texas Education Agency, TEA, has made available pdf files of some recent tests and also has a number of tests archived. This material would be good for preparing for the TAKS test and for practicing algebra and geometry.
Pearson has made available some pdf files of study guides and has some online, interactive study guides. (If those links do not work, start on the TAKS Study Guides page, then click on “Interactive Study Guides,” or click on “Printed Study Guides” followed by “Study Guide PDFs.”)