In this lesson, students estimate multi-digit products by rounding factors to a basic fact and using place value patterns. They then discuss the reasonableness of their products. They begin by contextualizing the concept of estimation by using the population of their classroom and school. Next, they solve problems through estimations. For example, students round 456 x 42 to 450 x 40 and 500 x 40. They would choose the later to solve.