Formative Assessment 33

Assessment Problem: 

Challenge your students to think about the meaning of equal sign through the following questions. For each of the following tasks, decide if “=” is used appropriately. Discuss if there would be conditions under which “=” could be used or it is more appropriate to use other symbols.
a.     t=t
b.     2t= t
c.     a+b=b+a
d.     2w+(3+5x)=(2w+3)+5x
e.     x(x+2)=x^2+2x
f.      8x-6x=2x
g.     8x-5x=2x
h.     0=x^2+2x-5

Mathematical Issues: 

The question provides an opportunity to discuss the meaning of the equal sign more in depth using expression with variables. Discuss how can we compare expressions and use the equal sign appropriately in such situations.

Domain: 
Algebraic Relations
Theme: 
Meaning of equal signs
Common Core Standards: 
A-REI: Reasoning with Equations and Inequalities
Research References: 
Hattikudur, S., & Alibali, M. W. (2010). Learning about the equal sign:Does comparing with inequality symbols help? Journal of Experimental Child Psychology, 107, 15-30. Godfrey, David, & Thomas, Michael O. J. (2008). Student Perspectives on Equation: The Transition from School to University. Mathematics Education Research Journal, 20(2), 71-92.