We had a pretty much normal week with warm-ups, so I have five to share! This week we started working on decimals, and our warm-ups were related.
There are two notes to make about this warm-up: 1) that should say “expanded form” rather than “extended form”, and 2) I realized after I’d written it that they weren’t ready to talk about that yet. Sometimes I’ll do a warm-up about a brand new concept, especially if we’re going to talk about it that day in rotations, but that just didn’t make sense for this one. I was out with a sick baby, and we weren’t going to talk about it for another couple of days, so we skipped that part until later.
So this was the day when we came back to expanded form. I was glad that we waited, because I could tell from their responses that they didn’t have a clear idea about what it meant. Many wrote the number in words–which is word form instead of expanded form. Once I showed them what it was, many remembered, and so after the whole number we tried it with a decimal (the part at the bottom). The whole idea of expanded from with decimals is new (both to my students and to me!) and was added in because of changes we’re making to align closer with Common Core standards. Once you start talking about how it works, though, it’s really the same idea as with a whole number. Most picked up on it pretty quickly.