National Research Center for Career and Technical Education
Transportation, Distribution, and Logistics: Tire and Wheel Assemblies
Is bigger really better? By the end of this instructional activity, learners will be able to apply formulas for computing the diameter of tires and wheel assemblies. Begin by showing a slide presentation that will review definitions for...
National Research Center for Career and Technical Education
Hospitality and Tourism 1: Safety and Sanitation
Math and science come alive in this career-related lesson on sanitation. Along the way, learners explore bacterial growth rates using exponential notation and graphs. A link to a very brief, but vivid video shows just how quickly these...
National Research Center for Career and Technical Education
Hospitality and Tourism 2: Costing
The lesson plan provides a richly detailed narrative and sample problems for teaching or reinforcing how to work with percentages. In particular, your audience will compute the costs per serving of food and simulate setting menu prices...
Illustrative Mathematics
Calculating the square root of 2
Does a calculator give you the exact value of the square root of 2? Here, learners must decide if 1.414236 is equal to the square root of 2. They must also explain why the square root of 2 could never be equal to a terminating decimal....
Illustrative Mathematics
Rational or Irrational?
Is 4 plus the square root of 2 rational or irrational? After your class has gained a basic grasp of rational and irrational numbers, use this worksheet to push them a little further in their understanding. Learners must identify sums and...
EngageNY
Completing the Square (part 2)
Give classes confidence in completing the square with a resource that develops the process of completing the square of more complex problems, including fractions and values greater than one. It then uses quadratic modeling for...
National Research Center for Career and Technical Education
Health Science: Back to Basics
This lesson focuses on unit conversion, proportions, ratios, exponents, and the metric system. Discuss measurement with your math class and demonstrate how to solve several health-science word problems. Give learners a chance to visit an...
Illustrative Mathematics
Operations with Rational and Irrational Numbers
Learners complete addition and multiplication tables that include rational and irrational numbers. They also answer a series of questions about the sums and products of irrational and rational numbers. One suggested modification would be...
Wolfram Research
Wolfram Math World: Rational Number
This site gives an overview of rational numbers, gives interesting facts about the rational numbers including countability and probability of a rational numbers denominator being even. The site also contains related links.
Cut the Knot
Cut the Knot!: What Is a Number?
Casual and clear but definitely upper-level discussion of rational, real, imaginary, and several other types of numbers. Links to related sites.
Math Is Fun
Math Is Fun: The Evolution of Numbers
Discusses what numbers are and how our understanding of them has evolved over thousands of years, from simple counting to negative numbers and irrational numbers, for example. Includes a set of practice questions where students identify...
Cut the Knot
What's a Rational Number?
This question is answered by discussing and comparing rational and irrational numbers. For more advanced levels of Algebra, there are sections that discuss different lemmas of rational numbers and give their proofs.
CK-12 Foundation
Ck 12: Interactive Algebra 1 for Ccss
This is a complete, full-year Algebra 1 course with interactivity included in every lesson. Some lessons include videos, and all include interactives and inline questions that offer instant, per-answer feedback. Every lesson also has...
Houghton Mifflin Harcourt
Holt, Rinehart and Winston: Homework Help Independent Practice: Multiplying Rational Numbers
Get independent practice multiplying rational numbers. Each incorrect response gets a text box explanation and another try. Correct responses are confirmed.
Houghton Mifflin Harcourt
Holt, Rinehart and Winston: Homework Help Independent Practice: Dividing Rational Numbers
Get independent practice dividing rational numbers. Each incorrect response gets a text box explanation and another try. Correct responses are confirmed.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Numbers
Math Forum response to request for information on various number sets. Also defined and discussed are integers, natural numbers, whole numbers, irrational numbers, transcendental numbers, and algebraic numbers.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Rational Numbers and Square Ro
Math Forum response to which numbers, other than squared positive integers, can be simplified as rational numbers.
University of Cambridge
University of Cambridge: Nrich: Irrational Proof
This site contains a proof that the square roots of all prime numbers are irrational.
Texas Instruments
Texas Instruments: Real Numbers
Students learn to identify real numbers as rational numbers and irrational numbers. They review rational numbers as repeating decimals, and irrational numbers as non-repeating decimals. They also review commutative, associative,...
Other
Platonic Realms: Conic Sections
A proof to show that the square root of two is an irrational number, followed by a shorter and even more beautiful proof.
J Coffman
Joseph Coffman's Lecture Notes: Properties of Numbers
The lesson examines properties of real numbers. Students learn about rational numbers, properties of real numbers, and irrational numbers. Examples and an assessment are included.
National Institute of Educational Technologies and Teacher Training (Spain)
Ministerio De Educacion: Los Numerous Reales
In this module you will learn about rational and irrational numbers.
CK-12 Foundation
Ck 12: Algebra: Square Roots and Irrational Numbers
[Free Registration/Login may be required to access all resource tools.] Learn how to find square roots and identify irrational numbers.
CK-12 Foundation
Ck 12: Arithmetic: Addition of Rational Numbers
[Free Registration/Login may be required to access all resource tools.] Learn how to add rational numbers.