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Midpoint formula | Analytic geometry | Geometry | Khan Academy Teacherflix 4 Просмотры • 2 лет тому назад

Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now: https://www.khanacademy.org/ma....th/geometry/hs-geo-a

Midpoint Formula

Practice this lesson yourself on KhanAcademy.org right now:
https://www.khanacademy.org/math/geometry/analytic-geometry-topic/cc-distances-between-points/e/midpoint_formula?utm_source=YT&utm_medium=Desc&utm_campaign=Geometry

Watch the next lesson: https://www.khanacademy.org/math/geometry/analytic-geometry-topic/cc-distances-between-points/v/ratios-of-distances-between-colinear-points?utm_source=YT&utm_medium=Desc&utm_campaign=Geometry

Missed the previous lesson?
https://www.khanacademy.org/math/geometry/analytic-geometry-topic/cc-distances-between-points/v/distance-formula?utm_source=YT&utm_medium=Desc&utm_campaign=Geometry

Geometry on Khan Academy: We are surrounded by space. And that space contains lots of things. And these things have shapes. In geometry we are concerned with the nature of these shapes, how we define them, and what they teach us about the world at large--from math to architecture to biology to astronomy (and everything in between). Learning geometry is about more than just taking your medicine ("It's good for you!"), it's at the core of everything that exists--including you. Having said all that, some of the specific topics we'll cover include angles, intersecting lines, right triangles, perimeter, area, volume, circles, triangles, quadrilaterals, analytic geometry, and geometric constructions. Wow. That's a lot. To summarize: it's difficult to imagine any area of math that is more widely used than geometry.

About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.

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Subtraction: Learn to subtract 1-digit numbers from twenty with regrouping. Teacherflix 4 Просмотры • 2 лет тому назад

This lesson teaches how to subtract 1-digit numbers from twenty with regrouping. Practice free: http://www.ilearn.com/subtract

This playlist teaches how to subtract numbers from two digits through 4 digits. The make a ten strategy covered in the Addition and Subtraction playlist is used in these lessons to teach regrouping. http://www.ilearn.com/subtract

The playlist is organized so that students progress from the simplest cases with the smallest number of digits and no regrouping to the more difficult cases with 4-digit numbers and regrouping in more than one place.

iLearn provides professionally designed math instruction for all markets, including home, K-12, and college. Our instructional programs combine the best scientifically-designed curriculum with state-of-the art delivery systems.

Our specialty is providing easy-to-use, highly effective support, for students who have difficulty learning math. It’s the easiest and fastest way to understand math and master math procedures.

This video is one of over 800 lessons from iLearn on math topics ranging from kindergarten through high school math.

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For free access to unlimited online practice and tests, along with free access to these lessons, go to:

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If you prefer to read, rather than watch this video, here’s the transcript:

Title: Learn to subtract 1-digit numbers from twenty with regrouping.

You can already subtract a one-digit number from ten.
In this lesson, you'll learn how to subtract a 1-digit number from 20, which is 2 tens.
Here's an example. 20 minus 3.
Twenty is 2 tens.
We start subtracting in the ones place.
We can't subtract 3 from 0, so we have to take a ten from 20 to make ten ones.
We cross out the 2 in 20 to show we took a ten and we put a 1 here to show we have 1 ten left in the tens place.
We put a 1 here to show that we made ten ones.
Now we subtract 3 from the 10 ones.
10 minus 3 is 7.
In the tens place there's nothing to subtract, so we bring down the 1.
That gives us 17.
So 20 minus 3 is 17.
Another example. 20 minus 8.
Twenty is 2 tens.
We start subtracting in the ones place.
We can't subtract 8 from 0, so we have to take a ten from 20 to make ten ones.
We cross out the 2 in 20 to show we took a ten and we write a 1 above it to show we have one ten left.
We show that we made ten ones by putting a 1 here.
Now we subtract 8 from the 10 ones.
10 minus 8 is 2.
There's nothing to subtract in the tens place, so we bring down the 1 we have left.
That gives us 12.
So 20 minus 8 is 12.
Last example. 20 minus 4.
We start with the ones place.
We can't subtract 4 from 0, so we have to take a ten from 20 to make ten ones.
We cross out the 2 in 20 to show we took a ten.
And we write 1 here to show there is 1 ten left, which is 10.
We put a 1 here to show that we made ten ones.
Now we subtract 4 from 10.
10 minus 4 is 6.
There's nothing to subtract in the tens place, so we bring down the 1 we have left.
That gives us 16.
So 20 minus 4 is 16.
In the rest of this lesson, you'll work problems like these. You can use these boxes if you want, but you don't have to.

http://www.ilearn.com/subtract

https://youtu.be/Y9WhHCgtE5g