Fractions, Percents & Other Calculations CHARLIE KASOV Defining Variable & Constraints in Math Word Problems1 How to Find Out if a Fraction Is Equivalent or Not Equivalent2 How to Round to the Nearest Inch3 How to Find the Surface Area of a Pentagon4 About the Author Charlie Kasov has been tutoring high school mathematics since 2004. He is qualified to teach several math subjects, including geometry, algebra, trigonometry and probability. ×