definition of unit

[lsharlow]

We are trying to find a general, student-friendly definition for unit. We were considering using this: any group of things or persons regarded as an entity. At first we were considering that the definition needed to include something that said it had to be a consistent size (“tens”, “inches”, “halves”, etc.) that you can count, but then we thought about counting “pumpkins” that wouldn’t be the same size. We just want to be sure that we are consistent with the terminology used in the CCSS. Thank you.

[Cathy Kessel]

Here’s a quick comment: I don’t think there is any grade in which students are required to know a general definition of unit. However, they see examples of different types of units over the grades as described in the section on units (pp. 10-11) in the draft front matter for the Progressions here: http://ime.math.arizona.edu/progressions/. So, over the grades, their understanding of “unit” expands.

[Bill McCallum]

I agree with Cathy here. Also, I would add to your definition that a unit is something replicable; you can measure out quantities using copies of the unit. For example, you can measure the length of a table in matchsticks.

[Author]

Posts