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3-36.

Consider the expression $5+4+2(-3)+7+(-5)$.

1. Draw the expression using $+$ and $-$ tiles.

The first three terms have been drawn for you.

$+ \quad + \quad + \qquad \quad + \quad + \qquad \quad -\ -\ -\\ \quad + \quad + \qquad \quad \ \ + \quad + \qquad \quad -\ -\ -$

2. Simplify the expression to find the number it represents.

The last two terms are drawn below. You can move the drawings from this part and the previous parts to help you make zeroes and determine the answer.

$+\ +\ +\ +\ +\ +\ + \qquad -\ -\ -\ -\ -$

3. Remove the last number from the expression $(-5)$ and find the sum again. Show how this would change your drawing. How much larger or smaller is the answer? Explain how your answer makes sense when compared to the answer in part (b).

You can use the drawings from the parts above to help you with this problem.

Use the following eTool to answer this problem.
Click the link at right for the full version of the eTool:  (CPM)