CCSS Math Answers - Go Math Answer Key for Grade 8, 7, 6 ... Go Math Grade 4 Answer Key. Common Core Grade 4 HMH Go Math - Answer Keys. Chapter 1 Place Value, Addition, and Subtraction to One Million; Chapter 2 Multiply by 1-Digit Numbers; Chapter 3 Multiply 2-Digit Numbers; Chapter 4 Divide by 1-Digit Numbers; Chapter 5 Factors, Multiples, and Patterns; Chapter 6 Fraction Equivalence and Comparison