Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
Number Sense, Properties, and Operations
- Understand the structure and properties of our number system. At their most basic level numbers are abstract symbols that represent real-world quantities
The whole number system describes place value relationships within and beyond 100 and forms the foundation for efficient algorithms
Use place value and properties of operations to add and subtract.