Classroom Discussion
Problem Solving Talk Points
Equation: Teacher example
[-(x+4)]/2= -8
2 x [[-(x+4)]/2] = -8 x 2
-(x+4) = -16
[-(x+4)]/-1 = -16/-1
x+4 = 16
(x+4) -4 = 16-4
x= 12
Common student error
[-(x+4)]/2= -8
[[-(x+4)]/2] -4 = -8-4
How did you decide what to do first?
Common student error
[-(x+4)]/-1 = -16/-1
-x-4= 16
Did you figure out that didn’t work? How did you figure out this wasn’t going to work?
common student error
(x+4) -4 = 16-4
x= 10
What did you do that helped you make sense of this problem?
10+4 =16
This incorrect statement helps make sense of the incorrect method.
16-4 =12
12+4=16