Math Mammoth Place Value 3 is a short worktext meant for third grade level that focuses on four-digit numbers. The first lessons cover place value and comparing four-digit numbers. The rest of the book deals with addition, subtraction, and word problems. First, students learn to write and read four-digit numbers. Then they learn about the concept of place value, write numbers in expanded form, and place them on number lines. One lesson is spent comparing numbers. Then we turn our attention to addition and subtraction, first using mental math. The lessons on mental math stress the similarities between adding and subtracting four-digit numbers and adding and subtracting smaller numbers. This helps build number sense. Several lessons are spent on adding and subtracting four-digit numbers in columns and practicing regrouping. Students also solve a variety of word problems involving four-digit numbers along the way. I advise that you do not assign all the exercises by default. Use your judgment, and strive to vary the number of assigned exercises according to the student’s needs. Good Mathematical Practices. The book has lots of opportunities to focus on accuracy (precision) and checking one’s own work. Addition problems can be checked by adding each column in a different order. Subtraction problems can be checked by adding. Sometimes children hurry through their work and thus make mistakes. Don’t assign so much work that it creates time-related stress. Less can be more! Emphasize to your student(s) that they can take time to compute carefully, and to check their own work.