Let's not bury the lede: yes, those are chocolate-filled blueberries and cheese-filled raspberries. A kid brought them in, we ate them, and they're gross.
OK but why? That's a slightly longer story, and I recommend that you start it over at Danielson's place. Basically, I gave kids an object to build a measurement system around. They named it, created a "made-up-of" (e.g. an inch) and a "made-out-of" unit (e.g. a yard). They made a measuring tape, they measured stuff with their units.
Then we made square units to measure area with, and then cubic units to measure volume. Along the way a ton of good math happened -- fractions, scaling area, units, multiplication, measurement, volume concepts -- and a good time was definitely had by all.
Important questions for us were:
- How should we make a helpful tape measure?
- What's the best way to create a unit of area?
- How come so many of the square small units fit into the square major units?
- Ditto with cubes.
Important observations for me:
- There was a strong desire to measure area in terms of the physical objects that were their measures of length.
- Pretty much everyone had a moment while they were making a square or cubic unit where they went "Wait this is totally way too big."
- The kids couldn't keep "square" and "cubic" straight. That's a distinction they don't really make in their regular language, and I've seen the same thing with older kids calling a sphere a circle.
- Measurement is simply a great context for fraction work.