Unit 3:  Thousands of Miles, Thousands of Seats (Addition/Subtraction Number Systems) 

A.  Students use place value relationships and multiples of 10, 100, and 1,000 to add and subtract large numbers.

• Explain the place-value relationships between 10, 100, 1,000, and 10,000 (K)
• Know the place values larger than 100,000: million, billion, trillion (K)

B.  Students practice and investigate various strategies for subtracting large numbers, including U.S. algorithm.

C.  Students refine various strategies and use what they know about place value to solve addition and subtraction problems involving large numbers.

• Know the meaning of the steps and notation of the U.S. algorithm for subtraction (K)

D.  Students will gain flexibility in choosing strategies when solving addition and subtraction problems.

E.  Students will demonstrate persistance while investigating multiple strategies.