Denise says that $2/3-1/2 = 1/3$ and gives the reasoning indicated in Figure (below) to support her answer.
Is Denise right? If not, what is wrong with her reasoning and how could you help her understand her mistake and fix it?
Please, don't just explain how to solve the problem correctly; explain where Denise's reasoning is flawed.
I know that $2/3-1/2$ is $1/6$ but need help with the rest of the problem.
The Figure is of a circle cut into $3$ parts and it has $2$ of the parts shaded to represent $2/3$ and then she takes away half of the shade away and says she has $1/3$ left or $1/3$ shaded.