Learning Resources Measuring Worms Measuring Worms. Students get a grasp on early math skills with these squishy, colorful worms that make counting, sorting and measuring fun. Includes worms in six colors and four sizes (1", 2", 3" and 4") and an Activity Guide packed in a convenient storage bucket. Includes worms in six colors and four sizes (1", 2", 3" and 4") and an Activity Guide packed in a storage bucket. 72 worms per set.