standard_description: Apply and extend previous understandings of addition and subtraction to add and subtract rational numbers; represent addition and subtraction on a horizontal or vertical number line diagram.
problem_activity: Problem 1
The same image of a cat is shown at three different zoom levels on a computer.
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What do you notice about what happens to the scale as you zoom in and out on the image?
Problem 2
Your computer shows you a map of Washington Park in Eugene, Oregon. The scale in the bottom right corner of the map tells us that the length of the bar represents 200 feet on the map.
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Clicking a resizing button on the computer screen will result in an image of Washington Park, where the exact same-sized bar now represents 150 feet.
a.   Do you think the size of Washington Park under the 150 ft. scale will appear smaller or larger than it was under the 200 ft. scale?
b.   Draw an accurate picture/map of Washington Park under this new 150 ft. scale. Use the handout.
c.   Was your guess in part (a) correct? Can you explain why the size of the map changed as it did?


aligns: no