**5.MD.**

**4**. Measure volumes by counting unit cubes, using cubic cm, cubic in, cubic ft, and improvised units.

We worked very hard today on these

*rompecabezas*! In Spanish that means tricky puzzles that "crack your head open"!
To begin, I gave the children snap cubes, isometric dot paper, and three puzzles to solve.

Most of the students were able to solve this first problem with ease, so I showed them how to draw it on the isometric dot paper.

However, Puzzle 2 is not so easy. I watched the children struggle with this one for over half and hour--with several saying it was too hard to do. Refusing to give them any assistance except to read the clues again, I insisted that they could do it.

The part that causes difficulty is the third clue that "each layer is a square." The children constructed numerous versions of what made sense to them, but always I would point out that their solutions formed rectangles, not squares....or that they had too many cubes.

Here are two proud hopefuls holding up their solutions. Esmeralda almost had it correct, but then she connected the three layers side-by-side instead of stacking them on top of each other.

Finally Patricio got it! A groan could be heard across the classroom when everyone saw the easy solution.

In the new Math Practice standards, the children need to develop habits of mind like real mathematicians.

**MP1**states

**Make sense of problems and persevere in solving them.**So I had no mercy and made them persevere. :)

Fatima was still struggling with Puzzle 2. Keep going, Fatima! You can do it!!!

She did finally make it. Well done, mighty woman of valor.

Martha's well drawn solutions for the first 3 puzzles.

I love your original Puzzle 4, Jonathan!

Good luck trying to write the clues. I can't wait to read them.

Great effort with trying to draw him on isometric dot paper, too.

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