2. Addition
3. Subtraction
3.4.2. Related Subtraction Facts
3.4.3. Subtract Multiples of 10
3.4.5.1. Subtraction Property of Zero
3.4.5.2. Subtraction Property of One
3.4.5.3. Subtraction by Itself
3.4.6. Subtraction Word Problems
5. Division
6. Measurement
7. Geometry
8. Time
9. Patterns
10. Data Handling