25. Voting Ruler

Design: Concentrate Design
Price: $5
The Voting Ruler is a simple tool that works as a traditional ruler for measuring but also as a yes-or-no diagnostic for students to signal whether or not they understand a topic taught in class. In response to a teacher's question, a student simply raises his ruler with either the end marked "yes" or the end marked "no" in the air. The teacher can then immediately gauge the understanding of individuals and the larger group.