High school mathematics Archives - Page 2 of 5

Algebra, Geogebra, High school mathematics

Embedding the idea of functions in geometry lessons

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GeoGebra is a great tool to promote a way of thinking and reasoning about shapes. It provides an environment where students can observe and describe the relationships within and among geometric shapes, analyze what changes and what stays the same when shapes are transformed, and make generalizations.

When shapes or objects are transformed or moved, their properties such as location, length, angles, perimeters, and area changes. These properties are quantifiable and may vary with each other. It is therefore possible to design a lesson with GeoGebra which can be used to teach geometry concepts and the concepts of variables and functions. Noticing varying quantities is a pre-requisite skill towards understanding function and using it to model real life situations. Noticing varying quantities is as important as pattern recognition. Below is an example of such activity. I created this worksheet to model the movement of the structure of a collapsible chair which I describe in this Collapsible chair model.

Show angle CFB then move C. Express angle CFB in terms of ?, the measure of FCB. Show the next angle EFB then move C. Express EFB in terms of ?. Do the same for angle FBG.
[iframe https://math4teaching.com/wp-content/uploads/2011/07/locus_and_function.html 700 400]
Because CFB depends on FCB, the measure of CFB is a function of ?. That is f(?) = 180-2?. Note that the triangle formed is isosceles. Likewise, the measure of angle EFB is a function of ?. We can write this as g(?) = 2?. Let h be the function that defines the relationship between FCB and FBG. So, h(?)=180-?. Of course you would want the students to graph the function. Don’t forget to talk about domain and range. You may also ask students to find a function that relates f and g.

For the geometry use of this worksheet, read the post Problems about Perpendicular Segments. Note that you can also use this to help the students learn about exterior angle theorem.

Algebra, High school mathematics, What is mathematics

What is mathematical modeling?

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While there is no consensus yet as to a precise definition of this term, mathematical modeling is generally understood as the process of applying mathematics to a real world problem with a view of understanding the latter. One can argue that mathematical modeling is the same as applying mathematics where we also start with a real world problem, we apply the necessary mathematics, but after having found the solution we no longer think about the initial problem except perhaps to check if our answer makes sense. This is not the case with mathematical modeling where the use of mathematics is more for understanding the real world problem. The modeling process may or may not result to solving the problem entirely but it will shed light to the situation under investigation. The figure below shows key steps in modeling process.

Mathematical modeling approaches can be categorized into four broad approaches: Empirical models, simulation models, deterministic models, and stochastic models. The first three models can very much be integrated in teaching high school mathematics. The last will need a little stretching.

Empirical modeling involves examining data related to the problem with a view of formulating or constructing a mathematical relationship between the variables in the problem using the available data.

Simulation modeling involve the use of a computer program or some technological tool to generate a scenario based on a set of rules. These rules arise from an interpretation of how a certain process is supposed to evolve or progress.

Deterministic modeling in general involve the use of equation or set of equations to model or predict the outcome of an event or the value of a quantity.

Stochastic modeling takes deterministic modeling one further step. In stochastic models, randomness and probabilities of events happening are taken into account when the equations are formulated. The reason behind this is the fact that events take place with some probability rather than with certainty. This kind of modeling is very popular in business and marketing.
Examples of mathematical modeling can be found in almost every episode of the TV hit drama series The Numbers Behind NUMB3RS: Solving Crime with Mathematics

The series depicts how the confluence of police work and mathematics provides unexpected revelations and answers to perplexing criminal questions. The mathematical models used may be way beyond K-12 syllabus but not the mathematical reasoning and thinking involve. As the introduction in each episode of Numbers says:

We all use math every day;
to predict weather, to tell time, to handle money.
Math is more than formulas or equations;
it’s logic, it’s rationality,
it’s using your mind to solve the biggest mysteries we know.

The Mathematics Department of Cornell University developed materials on the mathematics behind each of the episodes of the series. You can find the math activities in each episode here.

The challenge in mathematical modelling is “. . . not to produce the most comprehensive descriptive model but to produce the simplest possible model that incorporates the major features of the phenomenon of interest.” -Howard Emmons

Assessment, High school mathematics

Conference on Assessing Learning

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The conference is open to high school mathematics and science teachers, department heads and coordinators, supervisors, tertiary and graduate students and lecturers, researchers, and curriculum developers in science and mathematics.

Plenary Topics and Speakers

1. The Relationship between Classroom Tasks, Students’ Engagement, and Assessing Learning by Dr. Peter Sullivan

2. Assessment for Learning: Practice, Pupils and Preservice Teachers by Dr. Beverly Cooper

3. The Heart of Mathematics Teaching and Learning: Assessment and Problem Solving by Dr. Allan White

4. Assessing the Unassessable: Students’ and Teachers’ Understanding of Nature of Science by Dr. Fouad Abd Khalic

5. Lesson Study in Japan: How it Develops Critical Thinking Skills by Prof Takuya Baba

6. Classroom Assessment Affective and Cognitive Domains by Dr. Masami Isoda

7. Assessment cum Curriculum Innovations by Dr. Ma. Victoria Carpio-Bernido

8. Strategies for teaching Mathematics to classes with Diverse Interests and Achievement – Having Problems with Problem Solving? by Dr. Peter Sullivan

9. Assessing Learners’ Understandings of Nature of Science – The New Zealand Science Hub by Dr. Beverly Cooper.

Aside from parallel paper presentations and workshops, there will also be parallel case presentations by science and mathematics teachers involve in Collaborative Lesson Research and Development (CLRD) Project of UP NISMED. CLRD is the Philippine version of Lesson Study.

Clickhere for conference and registration details.

Algebra, Geogebra, High school mathematics

Teaching simplifying and adding radicals

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The square root of a number is usually introduced via an activity that involves getting the side of a square with the given area. For example the side of a square with area 25 sq unit is 5 unit because 5 x 5 = 25. To introduce the existence of $\sqrt{5}$ , a square of area 5 sq units is shown. The task is to find the length of its side. The student measures it then square the measure to check if it will equal to 5. Of course it won’t so they will keep on adjusting it. The teacher then introduces the concept of getting the root and the symbol used. This is a little boring. A more challenging task is to start with this problem: Construct a square which is double the area of a given square. In my post GeoGebra and Mathematics: Squares and Square Roots I described a teaching sequence for introducing the idea of square root using this problem. There are 4 activities in the sequence. The construction below can be an extension of Activity 4. This extension can be used to teach simplifying radicals and addition of radicals. The investigation still uses the regular polygon tool and introduces the text tool of GeoGebra. Click links for the tutorial on how to use these tools. You will find the procedure for constructing the figure here.