## Math Forum - Problem of the Week

### Temperature Change

 It can be cold here in Pennsylvania! One day last winter the temperature was -3°C. In the evening the temperature dropped 6 degrees. After midnight the temperature rose 8 degrees. By noon the next day the temperature had dropped another 4 degrees.

Use this Java applet from the National Library of Virtual Manipulatives to help you model the problem:

http://nlvm.usu.edu/en/nav/frames_asid_162_g_2_t_1.html

Question: What was the temperature at noon in degrees Celsius?

Notes:

1. Use the Free Play setting at the bottom of the page.
2. Once you select Free Play you can add individual chips (negative or positive) to the workspace or you can add pairs of chips.
3. If you drag a negative chip over a positive chip, watch how they cancel out. Try dragging a positive chip over a negative chip, too.
4. If you want to throw away any chips, drag them to the trash can in the corner.

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