Geometry Grade 4

15 Jan

Both classes are working on Geometry units.

Grade 4

We started off by using a right angle as a benchmark for comparing and naming angles.  I quickly realized that many students didn’t really understand what and angle was so I backtracked and we created a manipulative to model angles.  I cut out strips of bristol board and attached them together at a vertex so that the students could make angles.  We played around with these until everyone was comfortable with what and angle is.

Acute angle 5

Then we worked on what is a benchmark.  All the students lined up according to height (I tried to take a panoramic photo but it didn’t work).   I asked the tallest (Paris), shortest (Ayla) and median (Griffin)  person to step forward and we used their heights as benchmarks for everyone else to compare their own height to.   For example, Bradley was in between Ayla and Griffin.  Then we went back to angles and compared a variety of angles to a right angle and a straight angle.   When the students were ready, we gave the angles names.

Next we tried to measure them.  I didn’t show them how as this was an investigation.  The students tried to measure the distance between the rays (lines) with their rulers and we quickly discovered that the distance was different depending on where you measured.  The closer to the vertex, the smaller the distance.


The students then named the angles on pattern blocks.  Many of them used the square to determine if the angles were acute or obtuse.  If you put the square on top of the hexagon angles (lining up one side and the vertex)  you can clearly see that the angle is larger so it must be obtuse.

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Now it was time to try to understand degrees.  We talked about how we couldn’t use rulers for measure them and why that didn’t work.  The kids are great ideas and realized that it was because of the difference between the space near the vertex was smallest and got larger the further away we moved from the vertex.   We talked about what the shape was of an angle (smaller than 180) and decided to call it a wedge shape.  I pulled up the pattern blocks on the SMART board and we used the beige rhombus as a unit of measurement.  We called the units wedges.  We noted that a full circle was 12 wedges and that one of the angles on the blue rhombus was 4 wedges.  Exploring with non-standard units helps the students to develop a deeper understanding of measurement.


From here we moved onto degrees and looked a protractor.  Individual degrees are so small they are hard to visualize!

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Posted by on January 15, 2014 in Geometry, Math, Uncategorized


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