Fluently add and subtract multi-digit whole numbers using the standard algorithm

What you'll learn

1. Add multi-digit whole numbers (up to 1,000,000) using the standard algorithm, including problems that require regrouping (carrying) across multiple place values
2. Subtract multi-digit whole numbers (up to 1,000,000) using the standard algorithm, including problems that require regrouping (borrowing) across multiple place values
3. Explain why the standard algorithm works by connecting each step to place value — each column adds or subtracts units of the same size, and regrouping trades 10 of one unit for 1 of the next larger unit
4. Handle subtraction from numbers containing zeros that require regrouping across multiple columns (e.g., 5,000 − 1,237)
5. Check the reasonableness of addition and subtraction results using estimation and by using the inverse operation (adding to check subtraction)

Prerequisites

• Recognize that in a multi-digit number, a digit in one place represents ten times what it represents in the place to its right