Critical thinking is the process of actively conceptualizing, applying, analyzing, synthesizing, and evaluating information to reach a conclusion. It involves taking existing knowledge and using it to solve new problems. Critical thinking is important because it allows people to form opinions and conclusions based on facts. In the 21st century, critical thinking is especially crucial due to the abundance of information available online, including false information. Teaching students critical thinking skills will help them make effective use of information and question claims. An example of applying critical thinking is evaluating whether the US Constitution remains a living document by considering elements like the Elastic Clause and amendments. Technology like WebQuests can also facilitate critical thinking by guiding research on problems.