These activities/Icebreakers allows student to fill in what they "know" wither it is at the beginning of the year, anytime during the middle or as an end of the Year review. I have used it at each part of the year. There are no 'right' answers, just what they know at the time. Each activity is very open ended which I have always liked.
At the beginning of the year it allows me to just know what they know and what I do or don't need to cover. In the middle it gives me a better understanding of what they got or need to review. At the End of the Year it lets me know if I did a good job teaching or if they got it all.
Here are SEVEN of my favorite class proven items that have all been successful in their own way. Give each a try and let me know which you like for your own class(es).