The imaginary lines that run lengthwise and widthwise across the earth were crucial to navigation in the days before GPS. Take a look at how sailors used mathematic calculations to keep their vessels on course.
Printables:
Additional links:
Some basic information about latitude and longitude.
https://www.britannica.com/science/latitude
A kid friendly overview of latitude and longitude,
https://www.youtube.co/watch?v=MSA88mmFuyE
