This lesson plan helps students develop a conceptual awareness of divisibility through exploration. Students test a variety of numbers for divisibility (I prefer to let them use calculators for increased reliability) and then look for patterns to develop divisibility rules.
Relationships between factors and divisibility become evident as students notice that they can use their understanding of factors to predict what a number may be divisible by.
Materials for the lesson include posters for students to write on as they do the activity and number cards to test.
The graphic organizer included can be printed in multiple formats so that you can choose how much information you want students to write, vs. what you want to provide for them.