Precalculus is intended for college-level Precalculus students. Since Precalculus courses vary from one institution to the next, we have attempted to meet the needs of as broad an audience as possible, including all of the content that might be covered in any particular course. The result is a comprehensive book that covers more ground than an instructor could likely cover in a typical one- or two-semester course; but instructors should find, almost without fail, that the topics they wish to include in their syllabus are covered in the text. Many chapters of Openstax Precalculus are suitable for other freshman and sophomore math courses such as College Algebra and Trigonometry; however, instructors of those courses might need to supplement or adjust the material. Openstax will also be releasing a College Algebra and Trigonometry title tailored to the particular scope, sequence, and pedagogy of those courses.

This checklist outlines how and why it is important to develop essential questions.

This website highlights the importance of nine "Essential Skills" as identified by the Government of Canada. It discusses the importance of reading, writing, oral communication, thinking, document use, digital skills, numeracy, working with others, and continual learning. It features videos that explain each of the essential skills as well as teacher resources that show how these essential skills are used in various occupations or jobs.

Explore the rest of the Skills Canada to learn about skills competitions, explore skill profiles for various trades, and more.

This site offers geography and history activities showing how two years in history had an indelible impact on American politics and culture. Students interpret historical maps, identify territories acquired by the U.S., identify states later formed from these territories, examine the territorial status of Texas, and identify political, social, and economic issues related to the expansion of the U.S. in the 1840s.

Establishing Norms for Meetings, PLCs, or a Classroom
Establishing norms helps set clear expectations that everyone in the class or learning community can build together and agree to.

This short video and interactive assessment activity is designed to teach fourth graders about estimating measure by image: centimeters or meters?.

Students learn that buoyancy is responsible for making boats, hot air balloons and weather balloons float. They calculate whether or not a boat or balloon will float, and calculate the volume needed to make a balloon or boat of a certain mass float. Conduct the first day of the associated activity before conducting this lesson.

This short video and interactive assessment activity is designed to teach fourth graders about estimating measure by description - multiple choice.

This math problem determines the areas of simple and complex planar figures using measurement of mass and proportional constructs. Materials are inexpensive or easily found (poster board, scissors, ruler, sharp pencil, right angle), but also requires use of an analytical balance (suggestions are provided for working with less precise weighing tools). This resource is from PUMAS - Practical Uses of Math and Science - a collection of brief examples created by scientists and engineers showing how math and science topics taught in K-12 classes have real world applications.

The task is designed to show that random samples produce distributions of sample means that center at the population mean, and that the variation in the sample means will decrease noticeably as the sample size increases. Random sampling (like mixing names in a hat and drawing out a sample) is not a new idea to most students, although the terminology is likely to be new.

Students estimate the storage capacity of CDs and DVDs by assessing diffraction patterns of green and red laser beams.

Tag Line: Building number sense one day at a time.

The site provides a number of estimation activities involving height, number of objects etc. The activities may include a photo or video to help students develop some reference to solve the activity. The answers are provided, but the idea is that students utilize their estimation skills to determine the appropriate answer.

The site also includes a blog, a relationship between some american common core standards and estimation activities, as well as information on clothesline math activities as well.

ESTIMATION 180 is a place for both students and teachers to enjoy making sense of math and develop their number sense together. Pick from over 200 visual estimation tasks that invite all your students to be part of rich math conversations and learning.

Each task begins with a question where student must analyze the evidence in the photo to answer the question. It provides lots of success for students who have different levels of thinking, and allows them to succeed even without getting the correct answer.

After Darwin blew the doors off the scientific community, a lot of people did some weird and unscientific stuff with his ideas. Francis Galton and a few others decided natural selection could be used to make the human race "better" and came up with Eugenics.

Hank tells us about the city of Eukaryopolis - the animal cell that is responsible for all the cool things that happen in our bodies.

An interactive applet and associated web page that describe the Euler line. It shows a triangle whose vertices can be dragged. As you drag them, the centroid, circumcenter and orthocenter move appropriately, showing that they are always collinear, always lying on the Euler line. There are controls to individually turn on the construction lines for each center. This helps visualize the concept since if they are all drawn at once, the diagram would be hopelessly confused. The web page has a full description the Euler line and has links to separate pages which go into each center in depth. Applet can be enlarged to full screen size for use with a classroom projector. Diagram can be printed. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

We express the exponential function of an imaginary variable in terms of sine and cosine. The "complex exponentials" that result trace out a circle in the complex plane. Pointing to one of the positions in the complex plane, we obtain the identity exp(i pi) = -1.