Monday, February 10, 2014

Geometry: Study of Lines, Part Two

One of our geometry lessons this week was on the 3-positions of a straight line:  horizontal, oblique, and vertical.

defining horizontal lines

First the boys needed to learn the word "horizon."  I knew this lesson was coming up so I took advantage of some opportunities in the car previously to point out places where it appeared as if the Earth's surface and the sky meet.  We also reflected on the way the ocean looks when it meets the sky.  Me Too spent a lot of time looking at this last summer in Florida and trying to goad his brother into trying to paddle to Mexico.  This geometry lesson connected also nicely with our states of matter and particles work from last year.  We were reminded that the particles of a liquid are more loosely held together than those of a solid.  The equal pull of gravity across the water combined with the freedom of movement enjoyed by the water molecules means that, even if you tilt the pitcher, the water will level.  Me Too has his eye level with the top of the water and is learning that this is called "a horizontal line."

defining vertical lines montessori elementary homeschool

Ahem.  My children were apparently very focused on their work that day.  Kal-El is watching gravity's hand in the concept of "vertical" as the plumb bob (from the box of the geometric sticks) "settles" into the "vertical" position.  I highly recommend NOT using the plumb bob from your box of sticks.  I would love to meet the person who thought that stiff, heavy-gauge, plastic fishing line would ever become straight again after being tied up in a ball in that little box compartment and set them "straight".

defining horizontal lines Montessori elementary homeschool

We were happy to hold up some of the remaining contents of the box of sticks to the horizontal and vertical lines.
defining vertical lines Montessori elementary homeschool

The boys also learned that lines that are neither horizontal nor vertical are "oblique."

defining horizontal vertical and oblique lines

They were happy to illustrate all three types of lines with the box of sticks.

Montessori geometric sticks horizontal vertical and oblique lines

They were even happier to go crazy with the box of sticks when they were done.  I thought this was going to amount to wasted time, but had to eat my thoughts(?) (I would say "eat my words" but I didn't say it out loud.  Can you eat your thoughts?) when they proceeded to identify all of the horizontal, vertical, and oblique lines when they were finished.  Unprompted.  

Also unprompted, Kal-El identified his straw in his cup of water at Panera as "vertical."  Me Too squinted at his own straw and declared it "oblique."  Then Kal-El said, "We had better hope that this table top stays horizontal or all of our straws will be horizontal or oblique."  I guess that means the lesson stuck.

Montessori Monday


  1. I love their follow-up conversation ;)

    For our plumb line, I used some embroidery floss and a heavier-than-usual old-fashioned holy medal. Straight every time ;) I agree on the fishing line issue!

    1. I suppose I could have just used the prism already hanging from a proper line in our school room, but I knew the boys would LOVE a plumb bob so they can be just like "Tom Silva." Actually, funny story, one of the boys kept mistaking Tom Silva for their grandfather. In their defense, my dad does look a bit like Tom Silva AND my dad is very, very handy...always building something. We are going to go to the hardware store and get a proper plumb bob just like Bob Vila or Tom Silva :) Then I can set them to work discovering that our whole house is out of level.

  2. I am pretty sure there are no real plug lines made with fishing string. The ones I have seen use heavy gauge string. Ridiculous! Well, the people who designed it have surely never had to actually use one. So I'll blame it on a crime of ignorance. ;) I can't wait to get to all of these lessons! So much fun! The "unprompted" is the best part. :)

    1. The geometry lessons have been pure fun fun fun! You'll love it.

      I'm getting madder and madder about that plumb bob every time I see that photo now...

  3. I agree with the above comments, that unplanned, unprompted bit is just the moment when your teacher/guide/parent heart just sings with pride and joy. :) I point to those instances to remind myself WHY I do all this in the first place.
    T did that too with the geometry sticks way back when...he loved making planes, houses, and lots of other figures. Since we hadn't gone over what those angles, lines, figures were, he wasn't able to do what your boys are doing we put away the material. I think he was doing this in August or September, before we had really settled into our classroom.

    1. I might remember seeing a picture of that. I think the sticks are going to be one of my favorites. I think right now the colored bead bars are my favorite Montessori material of all time.

      My husband is always asking if there isn't "an easier way I could be doing all this." He doesn't like to see me working on school in my "free time." However, it is lessons like these and the conversations that follow that keep me at it.