I'm a first year user of Investigations, and I've been very frustrated with the term "typical" to describe data. Is it suppose to be the mode, because that's how the text seems to talk about it - the most x's on the line plot? My 4th graders are very ready for arithmetic mean, and I've had no trouble teaching it to them in the past with good understanding (they also need it for their state test) Why are we beating around the bush with this term? What have other teachers done to clarify this term for their kids? Do you just call it a kind of average? Do you accept almost anything a child says to explain the data if it makes some kind of sense? And what is the point of so many sets of mystery data? My kids guessed them with no trouble at all. I do have a high group of kids, and I felt like a lot of the work was way too easy for them. Thanks for any input.