WA.3.1. Core Content: Addition, subtraction, and place value (Numbers, Operations) Students solidify and formalize important concepts and skills related to addition and subtraction. In particular, students extend critical concepts of the base ten number system to include large numbers, they formalize procedures for adding and subtracting large numbers, and they apply these procedures in new contexts.
3.1.B. Round whole numbers through 10,000 to the nearest ten, hundred, and thousand.