Trades, Jumps, and Stops: Early Algebra is one of eight units in the Contexts for Learning Mathematics Investigating Number Sense, Addition, and Subtraction (K3) The story The Masloppy Family Goes to New York City sets the stage in this unit for a series of investigations to develop several big ideas and strategies important in the algebra strand. Seven-year-old Nicholas Masloppy (fondly known as the Organizer) and his...