# 3 Act: All the Little Duckies

I was in a 2nd grade room the other day and a teacher was presenting a lesson on measurement using customary units.  Students were using rulers to measure to the nearest inch.  One of the students asked, “what if it is over 4 inches but not 5 inches?”  The teacher said, “you choose.”   I walked over and whispered, “actually let’s round up if it’s at a half and down if it’s before half because when they use rounding in 3rd grade next year, that will provide them the visual representation to refer back to.”

The Common Core Standards specifically state in 1.MD.A.2 to ” Limit to contexts where the object being measured is spanned by a whole number of length units with no gaps or overlaps.”  That is the reason that I used standard 2.MD.A.2 for this task.  In my opinion, this task is very appropriate for first grade and kindergarten students as well.  That conversation cannot happen early enough!

Act 1:

About how many ducks long is the math rack?

About how many cubes long is the math rack?

Act 2:

About how many ducks long is it?  Why did you choose that number?

There are 4 more cubes than ducks.

About how many cubes long is it?

Act 3:

Were you correct?

If so, what were you thinking?

If not, what was your thinking?