VT.7.6. Mathematical Understanding: Arithmetic, Number, and Operation Concepts: Students understand arithmetic in computation, and they select and use, in appropriate situations, mental arithmetic, pencil and paper, calculator, and computer.
M2:3. Demonstrates conceptual understanding of mathematical operations involving addition and subtraction of whole numbers by solving problems involving joining actions, separating actions, part- whole relationships, and comparison situations; and addition of multiple one-digit whole numbers.
M2:6. Mentally adds and subtracts whole-numbers facts through twenty with accuracy.