Curated OER
Circles: Radius, Diameter and Circumference
Fascinating discussion regarding the origin of Pi accompanies a detailed explanation of how to find the circumference of a circle. Since this is the first installment in a series on circles, the concept of circumference is separated into...
Khan Academy
Area of a Circle, Perimeter, Area, and Volume, Geometry
This production, the second installment in a series of circles, demonstrates the process of finding the area of a circle. It is effective as an introductory tool. However, it needs to explain the reasoning behind the formula because that...
Curated OER
Tau vs. PI
What�s wrong with Pi? In this video, Sal considers the question whether the number Tau (_), is a better number to use in our trigonometric model then the traditional PI (�). First, Sal reviews the definition of Pi, the trigonometric...
Khan Academy
SAT Prep: Test 1 Section 3 Part 4
Pushing through to problems 11-12 on page 398 of The Official SAT Study Guide, Sal goes into comprehensive detail on each problem. Problem 11 involves geometry, including the function of pi, and problem 12 involves non-constant slopes....
Khan Academy
SAT Prep: Test 4 Section 4 Part 4
Sal takes a little more time to explain the next two problems as he nears the end of this practice SAT session. He spends about 5 minutes drawing, solving, and discussing problem 17 (geometric line segments) and the next 5 minutes on...
Khan Academy
SAT Prep: Test 4 Section 2 Part 4
Taking time to thoroughly explain and work through problems 15-16, Sal models careful reading and problem solving. He begins problem 17 but continues it in the next video.
Khan Academy
SAT Prep: Test 5 Section 3 Part 5
Problem 15 on the practice SAT (page 657) prompts students to solve a word problem using a number of given constraints. Additional problems involve finding the radius of a circle (given the radius of a smaller circle) and prime...
Khan Academy
SAT Prep: Test 6 Section 7 Part 2
Helping students realize the common missteps in solving the average SAT problem, Sal creates a lens through which students can clearly see the correct and incorrect approach to each type of problem. He points out what a student might...
Khan Academy
SAT Prep: Test 8 Section 2 Part 1
Test eight from The Official SAT Study Guide includes eighteen problems, the first four of which are featured in this video. Basic algebraic expressions, linear equations, tangent circles, and coordinates on a plane test algebra and...
Khan Academy
SAT Prep: Test 6 Section 7 Part 5
On the home stretch of this practice session, Sal completes problems 18 and 19 on page 738 of The Official SAT Study Guide. He begins problem 20, but chooses to finish it in the next video instead of rushing the answer. As always, Sal's...
Khan Academy
SAT Prep: Test 2 Section 3 Part 5
Sal takes viewers into the home stretch of this practice test session from The Official SAT Study Guide. Problems 17-18 are algebraic equations, while problem 19 focuses on area in a given figure (with the use of pi).
Khan Academy
SAT Prep: Test 7 Section 5 Part 2
Complicated word problems and expressions are no match for Sal, and after watching this series, they will be no match for your students either! Sal deftly handles problems involving algebraic equations, averages, and circumference.
Khan Academy
Test 3 Section 2 Part 5
Both algebra and geometry problems are featured in this SAT practice video. Students who struggle to transition between skills on tests (average mean, then diameters and pi, then positive integers) would benefit from Sal's deft handling...
Khan Academy
SAT Prep: Test 5 Section 7 Part 5
Geometry problems on the SAT are often the most difficult for students to solve, let alone master. Focusing on several geometry-related skills (as well a few algebra problems), Sal makes this lesson a valuable resource for viewers who...
Khan Academy
SAT Prep: Test 3 Section 8 Part 3
Geometry and algebra are equally represented in this video, which covers problems 10-14 on the practice SAT. As always, Sal is the expert of quick, efficient ways to solve problems - especially helpful for students who have a difficulty...
Curated OER
Circumference of Circles
In this comprehensive video Duane demonstrates how to use a formula to determine the circumference of a circle. This clip is good because it shows how to determine circumference when the diameter is knows and when only the radius is known.
Curated OER
What is the Formula for the Volume of a Sphere?
The formula of a sphere is related to the formula of a cylinder? How? Oh, radius and pi. Watch this video and observe how the instructor illustrates just how these two formulas are connected. Then plug in the known values and solve this...
Curated OER
How Do You Find the Lateral and Surface Areas of a Cone?
The lateral surface area of a cone. Hmmm, what does that mean? Oh, it means the part you see if the cone was sitting on a flat surface, so it does not include the base. But if you want to include the base then it would be finding the...
Curated OER
Common Angle Measures
Using a circle with clock like hands, the tutor explains common angle measurements. She shows that a full circular rotation equals 360 degrees, a quarter rotation equals 90 degrees, a three-quarters rotation equals 270 degrees, and a...
Curated OER
What's an Irrational Number?
This video defines rational numbers. Through the definition and examples, learners should comprehend that irrational numbers are numbers that cannot become simple fractions. The video uses examples of very common irrational numbers, such...
Curated OER
What is the Formula for the Volume of a Cone?
All you need are a few values to find the the volume of a cone! Watch an informative math video that guides learners through the formula needed, as well as the relationship between the cone's volume and the volume of other...
Curated OER
How Do You Find the Volume of a Sphere?
The formula for the volume of a sphere is - volume equals four thirds pi times the radius cubed. That's a mouth-full. But if you are given the radius value of the sphere, all you have to do is plug it in and do the arithmetic. Just...
Curated OER
How Do You Find the Area of a Sector of a Circle?
How do you find the area of a sector of a circle? Use the formula of course. Then all you have to do is plug in the given values and do the math. Make sure you are following the rules of order of operation. The instructor will walk you...
Curated OER
What's an Irrational Number?
This video defines rational numbers. Through the definition and examples, learners should comprehend that irrational numbers are numbers that cannot become simple fractions. The video uses examples of very common irrational numbers, such...