칸아카데미 따라가기_Math1

출처: Khanacademy

Courses :2nd grade

Unit : Add and subtract wihin 20

제목: Adding within 20 using place value blocks

khanachademy_Math_class_ 캠쳐화면

강의에 나오는 영어자막을

그대로 옮겨서 따라 적었다.

입으로 따라하면서 연필로 적으면 더 기억에 남을것 같다.

 

What we wanna do in this video is think about what is equal to eight plus six, and to help us out, we have eight blocks shown right over here,

and we have another six blocks shown in this pink color.

So pause this video and see if you could figure it out.

So there’s a lot of ways to approach it,

but one way that I like to do it is,

let me see if I can make a group of 10

out of some of these blocks and then see how many of them are left over.

So if I want to make a group of 10,I would use all of these eight.

So one, two, theree, four, five,six,seven, eight and then I would need two more and I could get those two more from this six here,

and then I would have one,two,three,four left over.

And to see what that looks like,

you can see that we could take all of the eight

and then two of the six to make a group of 10,

and so I set that up as a whole bar.

So we know that our answer is going to have one 10.

So this tells us that that is,let me write it this way, one 10

and then how many ones?

Well, we could see that right over here.

We have four ones left over.

So that is four ones.

So if we think about place value, that’s one 10 and four ones or 14.

We have 10 and another four,which is the same thing as 14.