students may opt to take a foreign language course, either for a semester or the full school year. In the United States, American history is often the primary focus in eighth grade social studies. Other schools may also focus on other subject areas such as geography and world history. In Mathematics, 8th graders learn about scientific notation, geometry and angles, linear equations, measurement, functions, and exponents. In Science, 8th graders are in physical science and learn about forces and motion, energy, the electromagnetic spectrum, and chemical reactions. In English, 8th graders learn about themes, imagery, figurative language, textual evidence, analyzing sources, writing narratives, writing research reports, writing explanatory essays, writing persuasive and argumentative pieces, and compare and contrast. In the United States, 41 states have implemented Common Core curriculum standards for English/Language Arts and Mathematics in 8th grade. Key English/Language Arts Common Core standards for 8th grade students include: Ability to write arguments and to support claims with relevant evidence; support with logical reasoning using accurate, credible source Write narratives to develop real or imagined experiences using relevant details and structured event sequences Ability to write in a manner that the organization, development, and style are appropriate to the task, purpose and audience Conduct short research products to answer questions, drawing on multiple print or digital sources; ability to assess credibility of each source Key Mathematics Common Core standards for 8th grade students include: Ability to use linear equations and systems to represent, analyze, and solve various problems Students recognize (y/x=m) or (y-mx) as special linear equations (y=mx+b) and can interpret and express a relationship in terms of the situation Students understand the concept of a function as a rule that assigns exactly one output for one input Knowledge of distance and angles and ideas of translations, congruence, rotations, reflections, similarity Apply the Pythagorean Theorem to find distance between points on the coordinate plain, find lengths, and analyze polygons Oceania In Australia, this is called Year 8, which is the second year of high school. In New Zealand, Year 9 is the equivalent of eighth grade, with students aged 13 or 14 at the beginning of the year. It is the first year of high school. Students in Year 9 typically study English, mathematics, science, social science, health and physical education, arts and technology. South America In Brazil, the equivalent is (eighth grade). All students must be 13 years old