Talk about how composers are so busy that they do not have enough time to keep writing the same material over and over.
Musicians like to use shortcuts when they write music.
If a portion of a song is going to be sung twice the composer will use these repeat signs or repeat signs and multiple endings. Maybe you have seen those boxes with one and two over them, well those are for repeating. Show the kids a copy of music with either repeat signs or repeat signs and multiple endings. Say the verse together with me and find its meter where the strong pulses are. Since they said two we will put a two next to the first line to remind us of the meter.