Students work in pairs and then share a few strategies. Next 18x5 is added to the list and students are asked how 20x5 and 2x5 can help to find 18x5. In the next activity, students work in pairs on various clusters always trying to solve the last product in the cluster. A second, more difficult, student sheet is optional. In the next activity, students work in pairs to list products that could help solve 34x25.
Additional problems are optional.
The remaining activities address division clusters. As homework, students solve two clusters, one for 65x20 and one for 77x25, and write about how they used the products in the cluster to solve the problems. Later, in Unit 5 of the curriculum, more material on multiplication is given. Students have done more work finding multiples by this point. In Investigation 2 multiplication and division strategies are mentioned, however, this is really intended as a division solution.