This book represents a comparative study about mathematics education in two countries, the U.S. and Albania. Samples consisted of ninth graders which, in their respective countries, in the school year 2006-2007, were taking the subject matter of algebra. The measurement instrument consisted of the same algebra test followed by the same student questionnaire. The objectives of this study was comparing of the algebraic achievement of students across two countries and comparing and identifying educational practices associated with the algebraic achievement of students in each country. The analyses of data show that although students in the two countries exhibited comparable overall achievement on the test of algebra, their achievement on specific domains was different; in addition, algebraic achievement of students in the two countries was predicted by different numbers and types of educational practices.