#### Understanding

Students develop an understanding of “solution-preserving moves” by thinking carefully about the structure of relationships expressed by an equation and how to exploit that structure to find a solution.

### What to look for

Be sure students explicitly state what x represents in in the previous two questions. One example of confusion might be in the question above where x could represent the number of brownies Steve got or the total number of brownies his team made.

### Sample Assessment

What number makes the following equation true?

$\frac{1}{\mathrm{12}}$ + x = $\frac{3}{4}$Answer: $\frac{2}{3}$