Ratios as Seen in Scale Factors

Ratio underpins so much mathematics in our real world that it deserves occasional return visits. These sites deal mainly with making and building and constructing; mathematically, they concentrate on scale factor, a topic chosen by NCTM as a Focal Point for Grade 7. The very last site is just for teachers who may want a refresher at the professional level on basic but essential concepts. Please let us know any of your favorite sites for exploration!

All About Ratios
Designed to introduce the concept of ratio at the most basic level, this activity could open the idea to younger middle school students. Each multiple-choice problem shows sets of colorful elements and asks students to choose the one that matches the given ratio. The activity is from the collection titled Mathematics Lessons that are Fun! Fun! Fun!

Statue of Liberty
This activity asks students to determine if the statue’s nose is out of proportion to her body size. It carefully describes the mathematics involved in determining proportion, then goes on to pose problems on  enlarging a picture, designing HO gauge model train layouts, and analyzing the size of characters in Gulliver’s Travels. The page features links to a solution hint, the solution, related math questions, and model building resources. Other ratio problems in the Figure This! Series include Tern Turn, Capture Re-Capture, Drip Drops, and Which Tastes Juicier?

Understanding Rational Numbers and Proportions
To work well with ratios, learners need a solid basis in the idea of rational number. This complete lesson includes three well-developed activities that investigate fractions, proportion, and unit rates—all through real-world problems students encounter at a bakery.

Scaling Away
For this one-period lesson, students bring to class either a cylinder or a rectangular prism, and their knowledge of how to find surface area and volume. They apply a scale factor to these dimensions and investigate how the scaled-up model has changed from the original. Activity sheets and overheads are included, as well as a complete step-by-step procedure and questions for class discussion.

Size and Scale
A more challenging and thorough activity on the physics of size and scale! The final product is a scale model of the Earth-moon system, but the main objective is understanding the relative sizes of bodies in our solar system and the problem of making a scale model of the entire solar system. The site contains a complete lesson plan, including motivating questions for discussion and extension problems.

Golden Rectangle (grades 6-8)
This virtual manipulative can help students visualize the golden rectangle. It shows how a golden rectangle is generated by using the golden ratio (the ratio of the longer side to the shorter side of a golden rectangle) to create smaller and smaller golden rectangles within an initial rectangle. Instructions for using this online manipulative are included on the site.

Similarity
In this workshop session, elementary and middle school teachers explore scale drawing, similar triangles, and trigonometry in terms of ratios and proportion. Besides explanations and real-world problems, the unit includes video segments that show teachers investigating problems of similarity. To understand the ratios that underlie trigonometry, participants use an interactive activity provided online. This is session 8 of Learning Math: Geometry, a free online course.


We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. Post updated 12/09/2011.

Dynamic Math and Science Learning With Simulations

Bob Panoff, executive director of Shodor and CSERD: Computational Science Education Reference Desk is passionate about using computational science teaching methods to stimulate student engagement in learning math and science from grades K to gray!

In a recent article for the Association for Supervision and Curriculum Development (ASCD) entitled “Simulations Deepen Scientific Learning,” he explains the role of simulations in making scientific theory understandable for students. Find out about all of Shodor’s computational projects at http://shodor.org/interactivate.

As an example of how one of the simulations work, click on the following link to see how a disease spreads in a virtual population with the Disease Epidemic Model simulation: http://www.shodor.org/featured/DiseaseModel/.

 

We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. Post updated 4/05/2012.

Math Games – Part II

You probably already incorporate games in your teaching. Games are a great way to focus students’ attention as few other teaching strategies can. The ones selected here deal directly with the math content covered in the middle grades. Each has a learning objective; each could be embedded in a lesson plan. Here are a few more games that you can add to your store of games that teach.

Fraction Game
For work on fractions, this applet is a winner! It allows students to individually practice working with relationships among fractions and ways of combining fractions. It helps them visualize what is meant by equivalence of fractions. A link to an applet for two-person play is also given here.

Polygon Capture
This excellent lesson uses a game to review and stimulate conversation about properties of polygons. A player draws two cards, one about the sides of a polygon, such as “All sides are equal,” and one about the angles, such as “Two angles are acute.” The player then captures all the polygons on the table that fit both of the properties. Provided here are handouts of the game cards, the polygons, and the rules of the game.

The Factor Game
A two-player game that immerses students in factors! To play, one person circles a number from 1 to 30 on a gameboard. The second person circles (in a different color) all the proper factors of that number. The roles are switched and play continues until there are no numbers remaining with uncircled factors. The person with the largest total wins. A lesson plan outlines how to help students analyze the best first move in the game, which leads to class discussion of primes and squares as well as abundant and deficient numbers.

Planet Hop
In this online one-person computer game, four planets are shown on a coordinate grid. A player must pass through each on a journey through space. The player must find the coordinates of the four planets and, finally, the equation of the line connecting them. Three levels of difficulty are available. This is one of 12 interactive games created by the Maths File Games Show.

Towers of Hanoi: Algebra (Grades 6-8)
This online version of the Towers of Hanoi puzzle features three spindles and a graduated stack of two to eight discs, a number decided by the player, with the largest disc on the bottom. The player must move all discs from the original spindle to a new spindle in the smallest number of moves possible, while never placing a larger disc on a smaller one. The algebra learning occurs as the player observes the pattern of number of discs to number of moves needed. Generalizing from this pattern, students can answer the question: What if you had 100 discs? The final step is expressing the pattern as a function.

Traffic Jam Activity
Why the jam? There are seven stepping stones and six people. Three stand on the left-hand stones and three on the right-hand; all face center. Everyone must move so that the people on the right and the people on the left pass each other, eventually standing on the side opposite from where they started. But no two people may stand on the same stone at the same time! This problem requires reasoning, but its solution also reveals a pattern that leads to an algebraic expression. A lesson plan is provided.

We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. Post updated 4/05/2012.

Let’s Talk Teaching: Games in Math Class

In my years of teaching grades 6 through 8, I generally used games only for reviewing before a test. What I didn’t realize was how effective games can be for teaching the content. Each of the games below has a learning objective; each could be embedded in a lesson plan for middle school math. And, as you know, games focus students’ attention as few other teaching strategies can. Use our comment box below to share with other teachers the games you use in class!

Polygon Capture
This excellent lesson uses a game to stimulate conversation about the properties of polygons. A player draws two cards, one about the sides of a polygon, such as “All sides are equal,” and one about the angles, such as “Two angles are acute.” The player then captures all the polygons on the table that fit both of the properties. Provided here are handouts of the game cards, the polygons, and the rules of the game.

Maze Game
This online activity allows the player to practice their point plotting skills by having them move a robot through a mine field to a target location.  Great for learning to visualize coordinates on the Cartesian plane!

The Factor Game
In this two-player game, one person circles a number from 1 to 30 on a game board. The second person circles (in a different color) all the proper factors of that number. When no numbers remain with uncircled factors, the person with the largest total wins. A lesson plan outlines how to help students analyze the best first move in the game, which leads to class discussion of primes and squares as well as abundant and deficient numbers.

Data Picking
In this interactive game, students first create a table using data they collect from the onscreen characters. They then select a scatter plot, a histogram, a line graph, or a pie chart that best represents the data. The amount of data increases and the type of data representation changes according to which of three levels of difficulty is selected.

Fraction Track
Working in two-player competition or individually students practice finding equivalent fractions and ways of combining fractions as they move their pieces across the board. Both sites use applets, but the basic game play can be set up using only paper game boards and chips.


We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. Post updated 11/10/2011.

Factors

Factors and their multiples are so important to students’ work with fractions and number theory. These concepts come under the National Council of Teachers of Mathematics (NCTM) Number and Operations Standard for the middle grades. The resources here are all hands-on, if only virtually. Important to their success is the classroom talk that the resources generate.

The Factor Game
This is more than a game; it is a full lesson plan, complete with handouts, including the game board, and questions for discussion. Students practice finding factors and then analyze the winning strategies. It’s this analysis that leads them to talk about prime, composite, abundant, deficient, and perfect numbers. The plan is downloadable and printable. (See the online version below.)

The Factor Game (i-Math Investigations)
This is the same game but online and interactive. One advantage here is that a single student can play against the computer. What is missing, however, is the winning strategy analysis, so rich in discussion. If you decide to use this version, you can simply borrow the discussion questions from the pdf version above.

Coloring Multiples in Pascal’s Triangle
Good practice in finding multiples of small factors! Students roll a number cube, then color in the multiples of that number in Pascal’s triangle. As they click on all the multiples of the number rolled, they also practice multiplication and observe the surprising patterns that form in the triangle.

Factor Tree (grades 6-8)
The activity starts with building a factor tree, but then moves to finding common factors and reviewing those old friends: GCF (greatest common factor) and LCM (least common multiple). The student must first find the prime factors for a pair of numbers. After two factor trees are built, the student drags the prime factors from each tree to a Venn diagram, showing the common factors of the two numbers in an overlapping area. Finally, the student enters the greatest common factor and the least common multiple, which can be checked immediately. This activity is interactive, visual, and good review!


We Want Your Feedback
We want and need your ideas, suggestions, and observations. What would you like to know more about? What questions have your students asked? We invite you to share with us and other readers by posting your comments. Please check back often for our newest posts or download the RSS feed for this blog. Let us know what you think and tell us how we can serve you better. We appreciate your feedback on all of our Middle School Portal 2 publications. You can also email us at msp@msteacher.org. Post updated 11/16/2011.