Estimating Fractions: Addition

The Estimating Fractions: Addition assessment is designed to elicit information about 2 common misconceptions that students have when using estimation to determine the sum of two fractions::

  • ●   Misconception 1 (M1): Calculate First by Adding Across, Then “Estimate” from the Resulting Fraction
  • ●   Misconception 2 (M2): Add Numerators OR Denominators, Then “Estimate” from the Whole-Number Sum

We strongly recommend that you reference the information in the assessment materials document to learn more about these misconceptions, including how they appear in student work and how to score the pre- and post-assessments.

In addition to the pre- and post-assessments in the appendix, the assessment materials document includes six sections:

●  Topic Background
a research-based framing of the topic and connections to the Common Core State Standards
●  Student Misconceptions
details about the misconceptions in the assessment set as well as a link to a video explaining and illustrating the misconception in the context of items

Video explaining Misconception 1Video explaining Misconception 2

●  Administering the Pre-Assessment
a detailed sequence of instructions for introducing and administering the pre-assessment with students
●  Scoring
an item-by- item explanation of the misconception being elicited, the correct response, how students with the misconception typically respond, and a detailed assessment analysis process including anchor responses across a range of evidence strengths; these sections also include a scoring practice set with explanations that can be used for training and calibrating scorers, samples of student work, and a scoring guide template to use for scoring the assessment
●  Sample Student Responses
examples of student responses with notes about connecting evidence in student work to possible misconceptions
●  Administering the Post-Assessment
a detailed sequence of instructions for introducing and administering the pre-assessment with students