We all tend to think in terms of straight lines. And because the maps students normally see have straight lines edges, top and bottom, the pages they appear on in textbooks, atlases and other publications all share this same characteristic, it is easy for student to forget that the Earth is a sphere and lines of latitude reflect this fact. To check this, have students find all of the states in this country that all or part of are located north of the southernmost point in Canada. Hint: Pelee Island, Canada, is located in Lake Erie at 41 45" North latitude. The results will surprise many students. But it will help them take a more careful look at latitude lines and how they often appear on some map projections as "straight" rather than as gradual curved lines. Related to this exercise is the question: Which one of the conterminous 48 states extends farthest north? Unless your students are geographically literate, they will reply, "Maine." But that is not correct. The northwest angle of Minnesota is the correct answer, In fact parts of North Dakota, Montana, Idaho and Washington all extend further north that Maine. Have students use latitude to determine which nation/city/physical feature is farthest north or south in other world areas they study. Again, watch those curves!