Critical Thinking Activities in Math. Fun activities that develop critical thinking in math! Cranium Crackers helps students develop strong computation and analytical skills necessary for outstanding success in math. Methods:Contains a large variety of mathematical and verbal thinking activities unlike any collection available anywhere. Students cannot solve these activities by rote. They must think their way through each problem, developing skills that help them solve any new computation and word problem they'll encounter. Teaching Support: Includes hints, answers, and subject indexes of math concepts and thinking skills. 224 activities. License: reproducible.