Gripping Geometry

Both of my kids know their basic shapes (square, triangle, circle) very well.   Briana even knows all of the basic extended shapes (pentagon, octagon, star, oval, rectangle, heart, and diamond).  Abigail gets the extended shapes correct some of the time but not always yet.  I credit the kids’ love of puzzles, specifically the Melissa and Doug puzzle that shouts out each shape’s name in a weird monotone if you put it in the correct space. At this point I think that there is a diminishing return in adding dodecahedron to their vocabulary or splitting the triangle into isosceles and equilateral and the rectangle into a parallelogram and a trapezoid.  That being said I do want to expand on their knowledge of shapes (and spending the day on shapes will reinforce what they already know too).  So this week I will literally expand the shapes for the kids-

Squares into cubes

Rectangles into boxes or cuboids

Circles into cylinders and spheres

Triangles into pyramids and cones

First we learn on paper.

I print out the image below and sit down with the kids.  I explain that shapes can be flat, which is called 2D or 2-dimensional or they can be 3D and not flat.  I point to each of the 2D shapes in the picture and ask the kids what shape they are.  Abigail alternates between telling me the shape name and the color of the shape.  It seems that she opts for color when she doesn’t know the shape’s name so that she can still get it correct.  Briana is delighted to see lots of new shapes, like the semicircle and the nonagon (“the no! no! agon?!  That’s silly.”) 

Briana asks why most of the shapes have “agon” at the end.  I tell her that most of our language, English, is made up of Greek and Latin roots.  The root word “gon” which means “angle”.  The letters before the “gon” tell you how many angles are in the shape, so a pentagon starts with “pent” which means 5.  So the word pentagon literally means 5 angles.  Then I show them octagon since it’s a shape they’re more familiar with because of stop signs.  “Oct” means 8 and “gon” means angle, so what is an octagon?  A shape with 8 angles.  Right!  We count the angles in the octagon to verify that it has 8.  Incidentally, I had to take a class in Greek and Latin roots in middle school and part of high school and I think that it’s the most valuable class I took as it relates to building my vocabulary and reading comprehension.  Right now my kids are a little young to learn them, but if you have older kids, check out http://www.learnthat.org/vocabulary/pages/view/roots.html#g for a great reference site for roots and watch your teenagers ergophobia (erg/o – work, and phobia - fear) vanish and their SAT linguistic (lingua – tongue) scores ascend (scend-climb).

Then I get us back on track.  We look at the 3D shapes part of the sheet and I show them the sphere, prism, cuboid, cube, cylinder, pyramid, and cone.  We talk about what shape those come from.

Next we expand the paper.

I had previously printed out the shapes below from pbskids.org.  They are the origami blueprints of the cube and the pyramid. 

  

http://pbskids.org/cyberchase/games/23dgeometry/index.html

Starting with the pyramid, I ask the kids what shapes they see the people in.  They correctly reply “triangles”.  I fold and tape the triangles so that they are not flat and voila, a pyramid.  Oooh.  Super cool stuff to toddlers.

I make cubes and pyramids for both girls.  Bree wants me to make all of the 3D shapes on the paper, but since I don't have the blueprints to do that, I tell her that we can go backwards from a 3D shape to a 2D shape too.

I let Briana deconstruct a tissue box.  She looks at the resultant cardboard flat and says, “Mommy, a box is a rectangle first.”

Next we take our learning into the real world.

We’re going to enjoy the giant golden sphere that has finally shown up in the sky and we go shape hunting outside.  Armed with a the list of shapes to find and their beach pails, the kids head to the backyard.

  

Sadly, after not too long, we get chased back inside by a swarm of bees.   Apparently Abby brought a glass of apple juice in her basket.  We couldn’t figure out why the bees wouldn’t leave us alone.

Back inside Briana decides on her own to make her own prism with a scrap of triangular paper that was left over and a lot of tissues.  I help her roll up her paper and tape it closed into a cylinder.  I used to love origami as a kid.

As Bree is enjoying her newfound hobby, Abby gets restless.  So I let Bree take the tape and a lot of paper into the car and we go on an Abby led Look and See Adventure (I have a blog with the same name that can tell you all about those) to find more shapes.  We find rectangular, square, and octagonal street signs, and cylindrical orange construction bins.  We decide that the leaves are mostly triangles and the trees are cylinders.  Houses are cubes with pyramids on top.  We talk about shapes all night.

Please let the beautiful, spherical sun be out again tomorrow!  Oh, I’ve been informed by Briana that the sun is not a sphere; it’s just a circle because there’s no back sticking out.  At least she had a solid reasoning as to why.  And yes, the use of “solid” was a really bad, but intended, pun.  :) 

<3 Pedigreed Housewife