In this video, the teacher explains how to solve multistep problems involving positive and negative rational numbers using the order of operations. The teacher addresses common mistakes students make, such as confusion with addition and subtraction. Through an example problem about Shani and the bikeathon, the teacher demonstrates the step-by-step process of solving the problem and emphasizes the importance of understanding each unique problem. By following the order of operations, students can confidently solve multistep problems with positive and negative rational numbers.