Math Information for Parents

• While learning remotely we studied 2D and 3D shapes.

• 2-D Geometry .

We learned to:

• identify and compare various polygons (i.e.,triangles, quadrilaterals, pentagons, hexagons, heptagons, octagons) and sort them by their geometric properties (i.e., number of sides; side lengths; number of interior angles; number of right angles);

• identify right angles and describe angles as greater than, equal to, or less than a right angle

• compare various angles, using concrete materials and pictorial representations, and describe angles as bigger than, smaller than, or about the same as other angles

• explain the relationships between different types of quadrilaterals (e.g.,a square is a rectangle because a square has four sides and four right angles; a rhombus is a parallelogram because opposite sides of a rhombus are parallel);

• identify congruent two-dimensional shapes by manipulating and matching concrete materials

3D Geometry and Spatial Reasoning

E1.1 Geometric Reasoning

We can:

• sort, construct, and identify cubes, prisms, pyramids, cylinders, and cones by comparing their faces, edges, vertices, and angles

• E1.2 Geometric Reasoning

compose and decompose various structures, and identify the two-dimensional shapes and three-dimensional objects that these structures contain

• E1.3 Geometric Reasoning

identify congruent lengths, angles, and faces of three-dimensional objects by mentally and physically matching them, and determine if the objects are congruent

Our next unit is TIME. In Grade 3, students need to learn to tell time using digital and analog clocks using hours, minutes and seconds. The Key concepts are:

• Clocks can answer two questions: “What time is it?” and “How much time has passed?”. The focus in Grade 3 is on the first question.

• A colon (:) is used to separate units of time. Generally, time is read in hours and minutes, so 12:36 means 36 minutes after 12:00. To describe time more precisely, another colon is used to show seconds, so 12:36:15 means it is 15 seconds after 12:36.

• Analog clocks use fractions of a circle to provide benchmark times: quarter past the hour; half past the hour; and quarter to the hour. Benchmark times are not evident in digital clocks.

• Analog clocks have a face with three different scales. Navigating these scales can make reading an analog clock challenging.

  • The shorter hour hand (0 to 12, numbered scale) measures broad approximate time.

  • The longer minute hand (0 to 60, unnumbered markings) measures time more precisely.

  • The optional second hand (same 0 to 60 scale as that used by the minute hand) is used for precise time.

• The 24-hour clock is widely used in transportation schedules and in the military. For many parts of the world, it is the standard way of describing time.

Note

• Digital clocks are easier to read but may be more challenging to understand. To know that 9:58 is almost 10:00 requires an understanding that there are 60 minutes in an hour. This is unlike the place-value system, which moves in groups of 10 and 100. Using both digital and analog clocks helps make the 0 to 60 scale visible.