Properties of Inequalities

The battle of process teaching vs. concept teaching rages on...especially when a school has used several snow days and feels the pressure of cutting corners to cover essential content by mandated deadlines. Unfortunately, that's exactly the result that should be expected when corners are cut...COVERAGE...as opposed to building conceptual understanding that will act as a foundation for future learning. There are no magical answers when it comes to rearranging best laid plans, but concept teaching is always better for the long-term benefit of the student.

Properties of Inequalities Concept Builder

This "Properties of Inequalities" discovery activity serves as an excellent example of when it would be easier and quicker to teach process rather than develop conceptual understanding. This activity requires a record sheet and integer dice. Students generate original inequalities and perform a variety of operations to create transformed inequalities. Students analyze the results as to whether the transformed inequality has a same or different inequality symbol. Next students prepare short summaries on Post-It notes to sort as a whole class and generalize conclusions based on the results in each category.Try this one. Leave a comment to provide feedback...the good, the bad, and the ugly!

This activity highlights Common Core State Standard 7.EE.B.4b included in MATH-7.

The Distributive Property

How do you teach the distributive property? When planning lessons, be sure you are maintaining perspective. Ask: What have your students already experienced with the content? This is particularly critical when students have gaps and require support to bridge that gap. You will need to have the perspective of how the related content has developed over the years/courses so that you can replicate that progression for struggling students via individualized learning. Ask: What leaps will your students make in upcoming courses that stem from what you do with the content now? It is important to identify future learning so that you can ensure adequate depth in your course. Let's review the progression of the distributive property...

3.OA.B.5

In Grade 3, students use the distributive property as a strategy for multiplying. This is the concept builder for the distributive property. If students were unsuccessful when working strictly with numbers, then their efforts in applications with variables will be a stretch at best. Or worse yet...what if students memorized multiplication facts and never made sense of the concept through the distributive property?!?

6.EE.B.5

In Grade 6, students use the distributive property to produce equivalent expressions. Notice the example includes using the distributive property to toggle between factored form (the result from division) and expanded form (the result from multiplication).

7.EE.A.1

In Grade 7, students continue with the same concepts learned in Grade 6 with an extension to using rational numbers. Should 7th graders be solving equations that require using the distributive property? Continue reading.

8.EE.C.7b

In Grade 8 (and Accelerated MATH-7), students will use the distributive property to solve linear equations with rational coefficients. Notice the standard says "whose solutions REQUIRE expanding expressions using the distributive property..." in order to solve the linear equation.

Differentiate the necessity of the distributive property.

Perhaps MATH-7 students should be asked to solve equations that are similar to the equation in the left column above; however, this begs the question "How do we hope students solve that type of equation?". We also hope MATH-8 students recognize the need for the distributive property before they start the process of solving equations that are similar to the equation in the right column above.

This discussion highlights the Common Core State Standards 7.EE.A.1 and 8.EE.C.7b included in MATH-7, MATH-8 and Accelerated MATH-7.

Building Vocabulary

I remember my days of teaching trigonometry with fond memories. The students always carried a perspective that refreshed my soul. One day in the depths of summarizing characteristics of trig functions a discussion about vocabulary erupted. A student claimed he should receive a foreign language credit for math because it was a whole new language!

Aligned to CCSS for Grade 7

Vocabulary is essential to deep understanding of math concepts and the ability to communicate that understanding. Math teachers integrate the teaching of vocabulary throughout their lessons. In a recent Genius Hour, we reflected on that integration and discussed methods that would support strategic efforts. From word walls to Frayer models to graphic organizers to activities via Kagan structures to fun games...we investigated 12 strategies that align with the research described on this Vocabulary Development post. We used a recent unit on Percent (7.RP.A.3) to model the strategies and an Excel spreadsheet that included vocabulary from the MATH-7 course as a possible starting point.

Which strategy would most improve vocabulary development in your classroom? How would you like to organize your efforts?

Pondering Probability

Probability is one of the major shifts in the Common Core State Standards for Mathematics. In previous years, probability concepts have started in early elementary and developed in complexity through the years. The foundational probability concepts now reside in Grade 7. This calls for another filter adjustment in the classroom.

So...let's get this probability party started! What's your favorite probability concept to teach? Why? What is a looming concern you have about probability? And what obstacles have you experienced when assessing student understanding of probability concepts in the past (CCSS or not)? Solutions?

Join the discussion in the comment section below!

Solving Percent Problems

Since percents are ratios, the concept of percents is deeply rooted in proportional reasoning. The Common Core State Standards require students to use proportional relationships to solve percent problems. Teachers can approach percent problems by using proportional relationships with ratios or equations; this post outlines a path using ratios.

Before teaching percent change, students should have prior knowledge of percents. Students should be able to find a percent of a quantity as a rate per 100. And students should also be able to find the whole when given a part and the percent. Both of these concepts are included in CCSS 6.RP.A.3; however, teachers may prefer to informally assess these skills prior to introducing percent change. The "Calculate This!" activity requires students to determine the fraction, decimal, and percent represented by the shaded portion of a figure. (Note: The document is organized to be printed double-sided with answers on the back of the corresponding figure.) The "Estimate This!" activity requires students to estimate percent problems and sort the estimates into four categories including less than 50%, between 50% and 100%, between 100% and 200%, and more than 200%.

Fraction, Decimal, and Percent Representations

Percents Sorting Activity

Percent change is a common real-world application. Percent increase applications include tax, markups, fees, gratuities and commissions. Percent decrease applications include discounts or markdowns. A procedural approach to the concept of percent change can quickly overwhelm students either through the series of steps or in the confusion of how to duplicate a "shortcut" on their own. For example, a 5% discount on a $45 hoodie purchased with 9.5% sales tax could have a process emphasis with the following steps: 5% of $45=$2.25; $45-$2.25=$42.75; 9.5% of $42.75=$4.06; $42.75+$4.06=$46.81 total OR 95% of $45=$42.75; 109.5% of $42.75=$46.81 total. And when students are asked to determine the discounted price or the amount of tax, they struggle differentiating the steps to extract the specific solution. This is a great reminder that process must first be grounded conceptually. Perhaps a geometric investigation using color tiles with focus on percent change in area could provide students with a visual reference point when encountering the hoodie problem.

Percent Change Investigation

One common percent change misconception that becomes problematic in the midst of percent error is the misunderstanding that the percentage of increase from an original area to a new area is the same percentage of decrease from the new area back to the original area. Teachers can informally assess students via a journal prompt and then provide remediation as necessary by using the RallyCoach structure for Kagan cooperative learning.

Percent Change Misconceptions

Percent error  shows how inaccurate an experimental measurement is. If the experimental measurement is more than the actual measurement, describe the inaccuracy by what percent increase the experimental (new) measurement is compared to the actual (original) measurement. If the experimental measurement is less than the actual measurement, describe the inaccuracy by what percent decrease the experimental (new) measurement is compared to the actual (original) measurement. The Mars Research Lab Activity poses a suspected issue in one plant that prompts students to analyze samples to determine percent error for each color of candy within the sample. This lab activity can be used independently or as the research for a culminating project.

Mars Research Lab Activity

These activities highlight the Common Core State Standard 7.RP.A.3 included in MATH-7.

Multi-Step Ratio Problems

Proportional relationships are the major focus in the Common Core State Standards for grade 7 math. And this requires teachers to be intentional about setting the stage to make connections across the concepts included in the Ratios and Proportional Relationships domain.

The Desert Run team activity, adapted from a practice problem in the Math Course 2 textbook by McDougal Littell, centers around three animals and their top speeds. When comparing the running distances provided in the activity, students may initially think the greyhound rules the desert. However, further investigation is required to compare distance per unit of time because the snapshot distances are collected in different time intervals. This activity prompts students to determine which animal is the fastest and how far each animal has traveled after 11 seconds.

• Students may calculate the unit rate for the speed of each animal to determine which one is fastest. And then they may continue to use the unit rates to determine the distance each animal travels in 11 seconds.
• Students may set up a proportion to determine the distance after 11 seconds and use those results to declare which animal is fastest.
• Students may use the unit rate to determine the fastest animal and then set up a proportion to determine the distances after 11 seconds.

An extension of representing rates graphically is included for teams who finish early. Be sure to share your favorite student-created scenario in the comment section.

This activity prompts rich discussion with an opportunity to critique the work of others and make connections between rates and proportions. A record sheet is included for convenient use with the Fan-N-Pick or Showdown structures for Kagan cooperative learning.

Rates and Proportions Activity

The most popular proportional relationship is found in the formula d=rt. If your students are unfamiliar with the formula, lead them to it by asking them to create a table of values that model the relationship between the distance in feet that the greyhound travels over time in seconds and then write the equation that models the relationship. Extend their typical y=ax equation to better model the situation...let "y" be represented by "d" for distance in feet, let "a" be represented by "r" for rate, and let "x" be represented by "t" for time in seconds. Consider the following discussion path to help students connect equivalent rates to the equation for proportional relationships.

Connecting Rates and Proportions

The concepts discussed in the Desert Run team activity build the foundation needed for multi-step ratio problems. Modeling the sample "Reading Three Books" Type 1 task from PARCC, this Solving Multi-Step Ratio Problems team activity uses the Simultaneous RoundTable structure for Kagan cooperative learning. This activity assesses conceptual understanding of unit rates and its application in a multi-step ratio problem.

Solving Multi-Step Ratio Problems

These activities highlight Common Core State Standards 7.RP.A.2b, 7.RP.A.2c, and 7.RP.A.3 included in MATH-7.

Proportional vs. Nonproportional Relationships

Middle school students are naturally concrete thinkers. Using manipulatives to represent situations is one method to extend students from concrete thinking to abstract thinking. The following activity prompts students to use color tiles to model relationships, transfer that model to a numerical table, and then differentiate the characteristics of proportional and nonproportional relationships within the context.

Investigation

This investigation provides your students with a common reference point for proportional relationships. A student record sheet is available to support the three "homework vs. video games" scenarios in the investigation. And suggestions for class discussion are included in the "Teacher Notes" section.

Proportional Relationships Record Sheet

The big ideas that are characteristic of proportional relationships can be summarized in a Frayer Model. Post this graphic while students are completing targeted practice with the key concepts. Then ask students to create a Frayer Model at the conclusion of the unit. You will be surprised by the detail they add to their own graphics!

Frayer Model

This investigation highlights Common Core State Standard 7.RP.A.2 that is included in MATH-7.