Category Archives: Math

Posts related to what we’re working on in Math.

Building 3D solids and nets

Today we build 3D shapes from Go Frames.  This is what we know about 3D solids:

  • you name 3D shapes by their base

For example:  This is a hexagonal prism – the yellow base is a hexagon

Screen Shot 2016-02-24 at 2.07.49 PM

(photo cred to Jack)

 

This is a pentagonal prism – the orange base is a pentagon.

Screen Shot 2016-02-24 at 2.02.09 PM

(Photo cred to Sophie)

 

  • we name 3D shapes by the number of faces – for example, Gracie built a 12-sided shape called a “dodecahedron”

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    (Photo cred to Gracie)

  • any solid  that has many sides – is called a “polyhedron “- Nolan built a shape with 20 faces:

Screen Shot 2016-02-24 at 2.15.05 PM

(Photo cred to Nolan)

  • we tried to find out how you name solids with lots of faces like Nolan’s – you need to use Latin!

 

  • shapes with rectangular faces are called prisms:

Screen Shot 2016-02-24 at 2.20.35 PM

(Photo cred to Brae)

Screen Shot 2016-02-24 at 2.21.45 PMThis is a cube – it has 6 congruent square faces

(Photo cred to Quinn & Austin)

Screen Shot 2016-02-24 at 2.25.13 PMThis is a Hexagonal Prism – it has 6 congruent square faces and 2 congruent hexagonal faces

(Photo cred to Tuesday)

Screen Shot 2016-02-24 at 2.28.33 PM

This is Pentagonal Prism – it has 5 congruent square faces and 2 congruent pentagonal faces

(Photo cred to Brody)

  • shapes with triangular faces are called pyramids

Screen Shot 2016-02-24 at 2.07.01 PM

(Photo cred to Jasmine)

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(Photo cred to Brett)

Screen Shot 2016-02-24 at 2.04.53 PM

 

This is a square-based Pyramid – it has 4 congruent triangles and 1 square

(Photo cred to Bella & Abby)

  • 3d solids are made up of 2d shapes called faces

Here are some photos of us at work buiding 3D solids and nets:

Addition Screencasts

Last week, we worked on learning different strategies for adding large (4-digit) numbers.  Most students rely on one of two strategies:  expanding the number adding each place value, then adding those totals, or the standard algorithm, which some of them refer to as the “dinosaur method”.  The standard algorithm is the most efficient “pencil and paper” strategy for addition, but it’s best not to use it, until you can explain what you’re doing when you “carry” or “regroup” numbers.  The kids who use the expanded form method have a good handle on place value, and can explain their thinking quite clearly.  I’ll be conferencing with students this week in an effort to move them to the standard algorithm.  In the meantime, I’ve created two “screencasts” that model the 2 methods for addition.  They are stored on YouTube, with links to them below.  If your child needs a “refresher” on how to add large numbers, suggest they take a look at these video links.