Replicate the warm up Playing with Blocks using small composite numbers. Place students in small groups and provide each group with a value (6, 8, 10, and 12 are good ones). Ask students to create every rectangle they can using their target number of blocks.

Once students have time to agree and make sure they have found all the factors, ask groups to share. Allow students to explain how they know they found every factor. Announce in this lesson, we will develop a method to ensure we find all the factors and don't miss any.

Remind students the factors of a number are all the block sizes we can use to build that number. For example, the factors of 6 are 1, 2, 3, and 6 as we could build a castle that is 6 units tall using 1-blocks, 2-blocks, 3-blocks, or one big 6-block. Remember (as much as possible) to redefine words in terms students can understand rather than leaning only on the mathematical definition. If homeschooling, you can target your child directly by using analogies which specifically speak to them and their interests. If your students don't have a lot of experience with blocks and building (such as LEGO or Minecraft) consider what will speak to them. If you have musically inclined students, you could use beats reminding them if we want to clap on the 6th beat we could clap every beat, every 2-beats, every 3-beats, or every 6-beats. Make sure they can convince themselves these are the only options (counting on 5th beats for instance would skip over 6). If your students are athletically inclined, present factors as a race. Mark off 6 lines on the ground and determine what sized steps could we take to land on the 6th line. More activities like this can be found in earlier units of MathBait™ Multiplication.