Students start off by observing the similarities and differences of longitude and latitude lines on maps and globes. They will develop and use a hemisphere model to construct explanations as to why longitude and latitude lines are measured in degrees. Students will construct latitude and longitude lines with their model using string, a protractor, and thumbtacks. Then, students read a passage about longitude and latitude and complete a Venn Diagram. Using the Venn diagram, students will write sentences constructed from the vocabulary words explaining the characteristics and significance of longitude and latitude lines. Next, students will make connections to the 6th grade Common Core Math Standards and use ratio and rate reasoning to solve problems related to longitude and latitude. These ratio and rate reasoning problems will also require students to write, read, and evaluate expressions in which letters stand for numbers, use variables to represent numbers and write expressions, and understand that a variable can represent an unknown number. Finally, using a coordinate grid world map, students will understand that positive and negative numbers are used together to describe quantities having opposite directions or values and use positive and negative numbers to represent quantities in real-world contexts, explaining the meaning of 0 in each situation. Check out more at scienceteachermama.com.