OREGON MATH STANDARDS (2021): [1.GM]
Overview
The intent of clarifying statements is to provide additional guidance for educators to communicate the intent of the standard to support the future development of curricular resources and assessments aligned to the 2021 math standards.
Clarifying statements can be in the form of succinct sentences or paragraphs that attend to one of four types of clarifications: (1) Student Experiences; (2) Examples; (3) Boundaries; and (4) Connection to Math Practices.
2021 Oregon Math Guidance: 1.GM.A.1
Cluster: 1.GM.A - Reason with shapes and their attributes.
STANDARD: 1.GM.A.1
Standards Statement (2021):
Distinguish between defining attributes versus non-defining attributes for a wide variety of shapes. Build and draw shapes to possess defining attributes.
Connections:
Preceding Pathway Content (2021) | Subsequent Pathway Content (2021) | Cross Domain Connections (2021) | Common Core (CCSS) (2010) |
K.GM.B.4, K.GM.B.5 | 2.GM.A.1 | N/A | 1.G.A.1 1.GM.A Crosswalk |
Standards Guidance:
Clarifications
- Students should distinguish between defining attributes of two-dimensional shapes and three-dimensional figures versus non-defining attributes (e.g., triangles are closed and three-sided, a defining attribute versus triangles are red, non-defining attribute).
- Students should be able to build and draw shapes based on defining attributes. Two-dimensional shapes should be limited to triangles, squares, and rectangles.
- Students should be able to identify a shape’s attributes, regardless of its orientation (i.e., flipped) or position (i.e., turned).
Terminology
- The terms below are used to clarify expectations for the teaching professional. Students are not required to use this terminology when engaging with the learning objective.
- Attributes – characteristics of two-dimensional shapes and three-dimensional figures, including geometric properties.
- Defining attributes – include number of sides, faces, vertices (corners), and angles.
- Non-defining attributes – include size, orientation, texture, and color.
- Students should identify these two-dimensional shapes based on attributes:
- half circles, quarter circles, circles, triangles, squares, rectangles (Students should know that a square is a type of rectangle, based on its attributes.), hexagons
- Students should identify these three-dimensional shapes based on attributes:
- Cubes, cones, cylinders, spheres, rectangular prisms
Examples
- Students differentiate between geometrically defining attributes (e.g., “hexagons have six straight sides”) and nondefining attributes (e.g., color, overall size, or orientation). For example, they might say of this shape, “This has to go with the squares, because all four sides are the same, and these are square corners. It doesn’t matter which way it’s turned”. (Please reference page 8 in the Progression document).
- Illustrative Mathematics:
- Student Achievement Partners:
2021 Oregon Math Guidance: 1.GM.A.2
Cluster: 1.GM.A - Reason with shapes and their attributes.
STANDARD: 1.GM.A.2
Standards Statement (2021):
Compose common two-dimensional shapes or three-dimensional shapes to create a composite shape, and create additional new shapes from composite shapes.
Connections:
Preceding Pathway Content (2021) | Subsequent Pathway Content (2021) | Cross Domain Connections (2021) | Common Core (CCSS) (2010) |
K.GM.B.6 | 1.GM.A.3, 3.GM.C.5, 4.GM.A.3 | N/A | 1.G.A.2 1.GM.A Crosswalk |
Standards Guidance:
Clarifications
- It is important to note that the size of the shape does not necessary distinguish between common and composite. Students do not need to learn formal names, such as, “right rectangular prism”.
Terminology
- Shapes that are made up of two or more common shapes are called composite shapes.
- Students will be working with shapes to compose and decompose shapes to form new shapes.
- Compose – put together
- Decompose – break apart
Boundaries
- Students should use these common two-dimensional shapes to create composite shapes:
- Circles, half-circles, quarter-circles, triangles, squares, rectangles (Students should know that a square is a type of rectangle, based on its attributes.), hexagons, trapezoids
- Students should use these common three-dimensional shapes to create composite shapes:
- Cubes, cones, cylinders, spheres, rectangular prisms, right circular cones, right circular cylinders
Progressions
- From the early beginnings of informally matching shapes and solving simple shape puzzles, students learn to intentionally compose and decompose plane and solid figures (e.g., putting two congruent isosceles triangles together with the explicit purpose of making a rhombus), building understanding of part-whole relationships as well as the properties of the original and composite shapes. In this way, they learn to perceive a combination of shapes as a single new shape (e.g., recognizing that two isosceles triangles can be combined to make a rhombus, and simultaneously seeing the rhombus and the two triangles). (Please reference page 8 in the Progression document).
Examples
- Illustrative Mathematics:
2021 Oregon Math Guidance: 1.GM.A.3
Cluster: 1.GM.A - Reason with shapes and their attributes.
STANDARD: 1.GM.A.3
Standards Statement (2021):
Partition circles and rectangles into two and four equal shares. Describe the equal shares and understand that partitioning into more equal shares creates smaller shares.
Connections:
Preceding Pathway Content (2021) | Subsequent Pathway Content (2021) | Cross Domain Connections (2021) | Common Core (CCSS) (2010) |
1.GM.A.2 | 2.GM.A.3 | N/A | 1.G.A.3 1.GM.A Crosswalk |
Standards Guidance:
Clarifications
- Students should explore and justify reasoning about the relationship of parts to the whole.
- Students should describe the shares using the words “halves,” “fourths” or “quarters.”
- Students should describe the whole as “two of” or “four of” the shares.
- Students should reason that partitioning a shape into more equal shares creates smaller shares.
Boundaries
- No shading of the shares is needed for this learning objective because the student is only required to partition the whole shape into equal shares.
- Students are not expected to write the fraction using fraction notation in first grade.
Examples
- Describe the equal shares created using the words halves, fourths, and quarters.
- Relate the equal shares to the whole using the phrases half of, fourth of, and quarter of.
- Describe the whole as two of, or four of the shares.
- Understand that halves and fourths are equal parts of a partitioned whole.
- Illustrative Mathematics:
- Student Achievement Partners:
2021 Oregon Math Guidance: 1.GM.B.4
Cluster: 1.GM.B - Describe and compare measurable attributes.
STANDARD: 1.GM.B.4
Standards Statement (2021):
Order three objects by length; compare the lengths of two objects indirectly by using a third object.
Connections:
Preceding Pathway Content (2021) | Subsequent Pathway Content (2021) | Cross Domain Connections (2021) | Common Core (CCSS) (2010) |
K.GM.C.8 | 1.GM.B.5 | N/A | 1.MD.A.1 1.GM.B Crosswalk |
Standards Guidance:
Clarifications
- Students should express the length of an object as a whole number of length units, by laying multiple copies of a shorter object (the length unit) end to end, by using non- standard units.
- Students should explore this concept with objects found in the real world to develop solid measurement reasoning.
Terminology
- Length measurement of an object is the number of same- sized length units that span an object with no gaps or overlaps (iteration).
- Iteration –the process of repeating a unit length end to end along an object to obtain a measurement.
- Transitivity can be explicitly discussed: If A is longer than B and B is longer than C, then A must be longer than C as well. (Please reference page 8 in the Progression document).
Boundaries
- Students should learn through exploration that the length measurement of an object is the number of same-sized length units that span it with no gaps or overlaps (iteration). For example, when students are measuring the height of a vegetable plant in their classroom garden, they may use snap cubes put together to determine how tall the plant is.
Teaching Strategies
- Students should use terminology such as, but not limited to, “longer than”, “shorter than”, “same length as”, “taller than”, and “equal to”.
- Appropriate tools to measure non-standard units can be items such as one-inch paper clips, one-inch tiles, centimeter cubes, etc. The units need to correspond to standard units of measurement.
Examples
- Determine when an object is longer or shorter than another object.
- Compare two objects to a third and use those comparisons against the third object to compare the two objects.
- Students at an elementary school are maintaining an aquaponics garden. To measure the heights of the plants growing in their garden, they use snap cubes to determine how many cubes high the plant have grown.
2021 Oregon Math Guidance: 1.GM.B.5
Cluster: 1.GM.B - Describe and compare measurable attributes.
STANDARD: 1.GM.B.5
Standards Statement (2021):
Express the length of an object as a whole number of non-standard length units, by laying multiple copies of a shorter object (the length unit) end to end.
Connections:
Preceding Pathway Content (2021) | Subsequent Pathway Content (2021) | Cross Domain Connections (2021) | Common Core (CCSS) (2010) |
1.GM.B.4 | 2.GM.B.4 | N/A | 1.MD.A.2 1.GM.B Crosswalk |
Standards Guidance:
Boundaries
- Limit to contexts where the object being measured is spanned by a whole number of length units with no gaps or overlaps.
- Include use of standard units such as inch-tiles or centimeter tiles.
Teaching Strategies
- Estimate, measure, and record lengths of objects using non-standard units, and compare and order up to three objects using the recorded measurements.
- Use a shorter object to measure the length of a longer object.
- Record the length of an object as the total number of shorter objects it takes to span the longer object without gaps or overlaps.
Examples
- Illustrative Mathematics:
- Student Achievement Partners:
2021 Oregon Math Guidance: 1.GM.C.6
Cluster: 1.GM.C - Tell and write time.
STANDARD: 1.GM.C.6
Standards Statement (2021):
Tell and write time in hours and half-hours using analog and digital clocks.
Connections:
Preceding Pathway Content (2021) | Subsequent Pathway Content (2021) | Cross Domain Connections (2021) | Common Core (CCSS) (2010) |
N/A | 2.GM.D.10 | N/A | 1.MD.B.3 1.GM.C Crosswalk |
Standards Guidance:
Clarifications
- The familiarity of the number line provides students with an opportunity to make sense of the concept of elapsed time. The connection to the traditional clock can be made by bending the clock number line into a circle.
Boundaries
- Students should tell and write time to the hour and half hour in everyday settings, paying attention to a.m. and p.m.
- Problems presented to students should avoid crossing over a.m. and p.m.
- Students are not required to know the term elapsed time at this grade level.
Teaching Strategies
- Begin with a one-handed clock (just the hour hand) and use a lot of approximate language such as:
- “It’s close to 10:00.”
- “It’s half-way between 11:00 and 12:00.”
- “It’s just a little after 1:00.”
- Connect using a number line to tell time with how the number line can be curved to look like a circular clock.
Examples
- Tell time in hours and half hours using an analog clock.
- Tell time in hours and half hours using a digital clock.
- Write time in hours and half-hours.
- At 3:00 PM we are going to the trampoline park. We will be there for 4 hours. What time will we be leaving the trampoline park? Represent this on a number line. (It will be 7:00 when we leave the trampoline park).
- Illustrative Mathematics: