- You will need to provide calendars for at least one complete year, showing moon phases or the date of the full moons. One can be found on the Web at http://www.googol.com/moon/.
- Have your students find the average number of days between full moons. They should do this by using data from one or more years.
- They should come to definite conclusions about the average number of days in the cycle. They should be able to recognize this to be the same as the length of a month.
- After the center is completed, discuss with the whole class the concept of the month and the fact that years in many cultures are based on the lunar time scale.