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CK-12 Algebra I, second edition

CK-12 Foundation

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Note that this resource was reviewed during the Spring 2013 review period. The resource may or may not have been updated since the review. Check with the content creator to see if there is a more recent version available.


This resource was reviewed by OSPI in Spring 2013. Learn more about the review process and the data analysis approach.

Background from OER Project Review Team
CK-12 Foundation is a non-profit organization that creates and aggregates curated STEM content. For this review, only their Algebra 1 Flexbook was examined. The CK-12 platform offers many supplemental video, audio, and interactive, learning objects and real-world applications that can be accessed to adapt and remix the Flexbook. This should factor into the viewer’s analysis of the review results. Editing tools are built into the online system to facilitate personalization of content. Multiple formats allow for creation of device agnostic materials.

Publishers' Criteria (Learn more)

Chart with scale from 0 (Strongly Disagree) to 3 (Strongly Agree). Focus: 1.6, Rigor & Balance: 1.2, Consistent Content: 1.73, Coherent Connections: 1.27, Reasoning: 1.07, Standards for Practice: 1.0.

EQuIP (Learn more)

Not Recommended (0.2)
Chart with scale of 'meets criteria' from 0 (None) to 3 (All). Alignment: 1.2, Key Area of Focus: 1.0, Instructional Supports: 1.0, Assessment: 0.4.
Chapter 8

Achieve OER (Learn more)

Chart with scale from 0 (Weak) to 3 (Superior). Explanation: 1.8, Interactivity: 1.4, Exercises: 1.0, Deeper Learning: 1.0.
Chapter 8

See standard error chart for the review scoring

Reviewer Comments (Learn more)

Extreme (0.2)

CK-12 follows the same format as most traditional algebra 1 texts. It includes 13 chapters with 4-8 lessons per chapter. Each lesson has clearly stated objectives, multiple sample problems, written explanations of the concepts being taught, and practice problems. The explanations and examples are clear and could be useful for students that missed class or are working independently on the course. The text provides the basics of an algebra 1 course and upon completion most students would understand the algorithms of algebra 1.

While theoretical connections are discussed in a way that students can understand them, the theory does not show up in the practice problems. The materials do not meet the criteria outlined by the Standards for Mathematical Practice, especially in regards to rigor. Most problems provide practice for algorithms but lack meaningful application. In addition, the practice problems do not require students to communicate their understanding, critique the work of others, or draw connections between standards. The number of practice problems is also insufficient in major areas to reach fluency.

The curriculum does contain the major content areas within Algebra but also includes several units that address material below grade level standards and several sections that are above grade levels standards.

There is no support for differentiation. CK-12 does not include answer keys, supplemental materials, or assessments.

I would use these materials in my classroom: Disagree
(On a 4 point scale: Strongly Disagree, Disagree, Agree, or Strongly Agree)

I found that CK12 offers a concrete, sequential way of teaching Algebra. It seems that a beginning teacher who is new to the Common Core Standards could teach it with ease. The Learning Objectives are posted at the beginning of every section, which is helpful for both the teacher and student. Additionally, CK12 offers FlexMath that involves engaging lessons, interactive practice, and adaptive assessments. Although this resource has a great outline for a traditional teaching approach, I found it lacked the rigor that the Common Core is directing us to teach. Also, it offered few application problems where students would have to demonstrate mathematical practices. Overall, CK12 is a great beginning to an absolutely free resource. I am excited about it’s potential in the coming years.

I would use these materials in my classroom: Agree
(On a 4 point scale: Strongly Disagree, Disagree, Agree, or Strongly Agree)

After looking over the general topics and layout of the text I focused on Chapter 8, Applications of Exponential Functions. There were lots of examples but all were of the “show and tell” variety. An exercise was presented and then a step-by-step solution was displayed. There were some connections made to previous lessons but the reader was asked to merely follow along. Much in the manner of the “stand and deliver” lecture where the only student involvement is to take notes.

  • Rules for exponents are derived from numerical examples without a rigorous approach. The quotient rule is explained as “the rules are a lot like the rules for simplifying products.”
  • Xs in the numerator and denominator are crossed out without a discussion of factoring.
  • Significant digits are taught without any explanation of why they are important or what use they have.
  • Some significant mathematical misconceptions were portrayed. “This makes sense because multiplying any number by a quantity less than 1 always makes it smaller.” Not true if the quantity and the number are both negative.
  • Some real life problems show up without any explanation of their usage, compound interest for example.
  • The majority of the practice problems are expressions to evaluate. Students were not asked to solve equations in this chapter.
  • I could not find any work for A-CED, A-REI, or A-SSE 3 and 4. The latter domain is especially important in the high school content standards overall as a widely applicable prerequisite.
  • All of the practice exercises provided for procedural practice without any differentiation, extra support, or extension.
  • The media is limited to a few links to “YouTube” type videos.
  • Not all of the links were active.
  • While I did find a teachers edition it appeared to link with the first edition, not the second.
  • Besides the “Review Questions” there are no other assessments present. No pre-formative, summative, or self-assessments. No rubrics, answer keys, or scoring guidelines.

This text reads like a general rehash of earlier, traditional algebra textbooks. It might make a good review book for a student who had already completed algebra and wanted to brush up on procedural skills. It would appeal to parents who wanted an “old fashioned” text with eight examples per section followed by a page of problems that match the examples exactly. While this book might have met our old state standards it does not come close to meeting the criteria for materials and tools aligned to the CCSS.

I would use these materials in my classroom: Disagree
(On a 4 point scale: Strongly Disagree, Disagree, Agree, or Strongly Agree)

The chapter is divided into 7 units, with 6-8 examples in each section with some having video clips and practice problems listed at the end. Learning objectives and introductions are in each section. Key concepts and vocabularies are in bold. Mathematical practices are not listed and not a suggested timeline.

Entry Task is not offered in the material. The layout of each section goes from “Learning Objectives” to example 1. The first 3 sections of the section focus on properties without alternative ways of learning the concepts, the word “remember” is used throughout the chapter. Section 4 is ‘Scientific Notation’ and is not a grade-level standard and the placement of this section is not a natural flow to this chapter. The concept can be incorporated into the chapter, a stand-alone section creates disconnect to the coherence. Section 5, ‘Geometric Sequences’ is an Algebra 2 standard using the PARCC framework. Again, this section does not foster coherence. The last two sections of the chapter focus on exponential functions with graphing using a table, comparing graphs of exponential functions and solving contextual problems.

Assessments are not built into the material. Practice questions are assigned with limited extension problems. There is no support for differentiation and how the lesson should be structured is not clear. (i.e., individual work, pairs or small groups? Or direct instruction throughout?)

Some explanations are not very easy for the students to understand. For example, “When b can be written as a fraction, we can use the Property of Negative Exponents to write the function in a different form. For instance, y= 5(1/2) ^x is equivalent to 5(2)^-x. These two forms are both commonly used, so it’s important to know that they are equivalent.” I am not confident that the students understand why these two equations are equivalent without further discussion.

I would use these materials in my classroom: Disagree
(On a 4 point scale: Strongly Disagree, Disagree, Agree, or Strongly Agree)

The CK12 curriculum provides coherent and focused development of concepts with connection to prior knowledge. However, the structure of the content is similar to a traditional textbook. The concepts are introduced through the use of repeated examples – most often with very little context. Additionally, any application of the content only shows up at the end of a chapter. This structure does not lend itself well to integrating the mathematical practices.

For example,

The chapter on exponential functions is broken down into sections as follows:

  • 8.1. Exponent Properties Involving Products
  • 8.2. Exponent Properties Involving Quotients
  • 8.3. Zero, Negative, and Fractional Exponents
  • 8.4. Scientific Notation
  • 8.5. Geometric Sequences
  • 8.6. Exponential Functions
  • 8.7. Applications of Exponential Functions
  • Each section follows a similar structure:

    1. Learning objectives (which are not tied to standards)
      • Lesson 8.1: Use the quotient of powers property, Use the power of a quotient property, and Simplify expressions involving quotient properties of exponents.
    2. Some required reading with a basic development of the ideas
      • Lesson 8.1: The quotient of powers property is explained with an example of expanding the exponential expression in the numerator and denominator followed by cancelling
    3. Numerous procedural examples
    4. Numerous procedural problems for student practice.
      • Lesson 8.1: 25 problems with applying the exponential rules to simplify expressions

    The lessons do not explicitly include opportunities for students to develop the mathematical practices. Further, if the teacher wished to integrate the practices it would take extensive additional time – developing opportunities for students to engage in the content beyond the procedural level with critical thinking, complex problems, and prompts for communication, reasoning, and justification. Furthermore, the instructional material is not at all tailored to multiple instructional approaches; rather, it is driven by example-based learning.

    I would use these materials in my classroom: Strongly Disagree
    (On a 4 point scale: Strongly Disagree, Disagree, Agree, or Strongly Agree)

Creative Commons License
This work by the Office of Superintendent of Public Instruction is licensed under a Creative Commons Attribution 4.0 International License.