Standard 3

Standards for Mathemathical Practice


Construct viable arguments and critique the reasoning of others.

What are students doing?

Students are listening or reading the arguments of others, deciding whether they make sense and asking useful questions to clarify or improve arguments. Students understand the processes involved for problem solving.

What is the teacher doing?

Teacher encourages students to discuss and debate.

Teacher probes for metacognitive understanding (Ask why?)

Teacher engages students to explore the practice/skill

Teacher provides a learning environment that facilitates discussion and investigation


Cost analysis comparison of cellular phone plans- students would formulate and defend a way of showing how their plan is most economical. Other students could argue for/against other cellular plans based on formulas created to show cost over time.

Could be multiple levels- for middle school, could create charts and graphs

for high school, could use systems of equations to solve and for AFM, could use piece-wise functions to solve/explain.