1.OA.D.8 - About the Math, Learning Targets, and Increasing Rigor

Grade 1 Number Concepts

1.OA.D.8

Full Standard

Determine the unknown whole number in an addition or subtraction equation relating to three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? – 3, 6 + 6 = ?.

 

Measurement Topic

This standard is reported on the report card in these quarters as follows:

1st Grade Students Learning 1st Grade Standards
Quarter 1 Quarter 2 Quarter 3 Quarter 4

 

 

Report Card Measurement Topic: Demonstrates understanding of addition.

 

Report Card Measurement Topic: Demonstrates understanding of subtraction.

 

Kindergarten Students Learning 1st Grade Standards
Quarter 1 Quarter 2 Quarter 3 Quarter 4

 

 

Report Card Measurement Topic: Demonstrates understanding of addition.

 

Report Card Measurement Topic: Demonstrates understanding of subtraction.

 

 

About the Math

Skills and concepts below are learning goals for this standard.

This standard is critical in developing students' problem-solving skills, algebraic foundations, and understanding of addition and subtraction.

  • Determine the unknown in an addition equation.
  • Determine the unknown in a subtraction equation.

These learning targets are not about the procedural finding of an unknown in an addition or subtraction equation. The learning targets are grounded in the understanding of the meaning of the equal sign and the relationship between operations. Students should leverage understanding of part-part-whole relationships to write and find the unknown in an equation. This standard is closely related to others including that which is related to problem solving. This concept is an extension of the decomposing of numbers and students will use their understanding of decomposition of numbers when finding the missing part. 

  • Explain how an unknown in an equation was determined using physical models, drawings, number lines, and/or number charts.

Students should begin work with this standard by connecting symbolic representations to physical models, drawings, number charts, and/or number lines. Students should also connect these representations to the problems being solved as well as the equations that reflect the models and the problems. 

Essential vocabulary for this standard includes equation and unknown. (online dictionary Links to an external site., Download HCPSS Vocabulary Cards

).

 

Progression of Standard within Grade 1

This progression informs how to develop the standard within the grade level. This progression is provided by HCPSS Elementary Mathematics.

Progression Throughout Year
Quarter 1 Quarter 2 Quarter 3 Quarter 4
  • Determine the unknown in an addition equation.
  • Determine the unknown in a subtraction equation.
  • Explain how an unknown in an equation was determined using physical models, drawings, number lines, and/or number charts.
* Apply to properties and facts.

Progression of this Standard Across Grades

This progression is informed by the Achieve the Core Coherence Map Links to an external site.. Information is not the complete standard.

Progression Across Grades
Grade 4

This concept is not taught prior to grade 1.

  • Decompose fractions. Add and subtract fractions (4.NF.3)
  • Recognize angle measure as additive.  Decompose angles (4.MD.7)

 

 

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