I want each of you to look at the board. On a piece of paper, write which square that you think does not belong here and say why.
x^2 = 4
2^x = 4
2^x = -4
4^x = 2
Would anyone like to share what they have found? For those that don't want to share, I will review what you wrote after.
I believe that 2^x = -4 does not belong because unlike the other equations it equals a negative number.
x^2 = 4
2^x = 4
2^x = -4
4^x = 2
Good! Does anyone agree? Disagree? Do any students have different answers?
I agree with the last answer!
x^2 = 4
2^x = 4
2^x = -4
4^x = 2
I think 4^x = 2 does not belong because the product is not 4.
Good answers! Now I want everyone to get into groups and come up with a reason for why each equation does not belong.
x^2 = 4
2^x = 4
2^x = -4
4^x = 2
I like the communication and group work from every student in this group.
Well we have ideas for two of the equations, does anyone have an idea for the others?
I think we should look at what we can substitute for 'x' and maybe that will tell us why others don't belong.
Maybe the equation x^2 = 4 does not belong because the equation starts with a variable.
x^2 = 4
2^x = 4
2^x = -4
4^x = 2
I've enjoyed listening to the discussions groups are having. Each group will now present what they've come up with as an assessment for the past week's worth of work.