Topic A begins by revisiting the commutative property. Students study familiar facts from Module 1 to identify known facts using units of 6, 7, 8, and 9. They realize that they already know more than half of their facts by recognizing, for example, that if they know 2 × 8, they also know 8 × 2 through commutativity. This begins a study of arithmetic patterns that becomes an increasingly prominent theme in the module. The subsequent lesson carries this study a step further; students apply the commutative property to relate 5 × 8 and 8 × 5, and then add one more group of 8 to solve 6 × 8 and, by extension, 8 × 6. The final lesson in this topic builds fluency with familiar multiplication and division facts, preparing students for the work ahead by introducing the use of a letter to represent the unknown in various positions
In this video segment from Cyberchase, there is a valuable Encryptor chip being auctioned off that the CyberSquad needs to purchase in order to save Motherboard. It looks like it will take at least 100 Snelfus to win the bidding. The CyberSquad plans to raise Snelfus by working each day to earn and save Snelfus over a period of 11 days. The squad must use their multiplication and division skills to solve their problem!
