Light Bulb Moment

A light Bulb moment I saw in my classroom was last year at Elliot Elementary. I was teaching prime and composite numbers. I first wrote the numbers 1-20 on the board and went over each number and aligned them in each category. I then wrote multiplication problems under each number. The students then began to say "ohhh prime numbers only have multiplication problem under that category." I then handed out a chart and had them write the composite numbers in green and the prime numbers in green. I finally had them write multiplication examples under each number and they really seemed to grasp the concept.