This would be a good warm-up after you have introduce the concept of factors and multiples (in the Power of Exponents math packet, for example). Invite everyone in the class to choose a whole number between 1 and 100, write it down, and then hold it up for everyone to see. (In a Zoom class, each student holds up a piece of paper with their number?)

Then ask them to look around the classroom – can they see someone who chose a number which is a factor of their number? Can they see someone who chose a number which is a multiple of their number? Take some time to discuss their findings, perhaps using the following prompts for discussion:

• Did anyone find it really easy to find multiples of your number? What number did you choose?
• Did anyone find it hard to find factors of your number? What number did you choose?
• If someone in the class chose 1: Which number could everyone connect to?

This warm-up comes from the Mathigon activity, How Many Rectangles? Mathigon is a fantastic resource for math teachers. Check out the Polypad set of manipulatives. I’m starting to teach with it and will be sharing some highlights this summer.