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# Adding with regrouping

CCSS.Math:

## Video transcript

so I have two numbers here the top number I have one two three tens and I have one two three four five ones three tens five ones or thirty-five the second number here I have two tens one two and I have one two three four five six seven ones two tens and 7 ones now what I want to do is I want to add all of these numbers to or I want to add these two numbers together I want to add 35 plus the 27 or another way of thinking about it I want to add I want to add all of these blocks together I want to add all of these blocks together so let's start let's start in the ones place right over here so I have five ones here I have seven ones here so if I had five ones to seven ones how many ones am I going to get I'm going to get twelve one so I'm going to get one two three four five six seven eight nine ten eleven and twelve now you might notice a problem here because if I take five plus seven I can't write the number 12 in just the ones place I just need to have one digit I can't have two digits there so what can we do well what we could do is take ten of these ones and group them into a 10 and put it and put them into the tens place what am I talking about well what we could do is we could take one two three four five six seven eight nine and ten so we could take these 10 right over here and group them together into one of these blar bars so let's do that so let's group them together into one of these bars and then stick that bar in the tens place so all I'm doing here all I am doing here is give me one second let's see all right I'm going to write so I'm going to because I'm taking these ten right over here and I am regrouping them into the tens place sometimes this is called carry so instead of writing ten ones I'm going to write as 110 so instead of writing it as ten ones I'm going to write it as 110 so what does that do for us well now I only have two ones in the ones place I only have two ones in the ones place but now I have one more ten in the tens place and I have one more ten in the tens place sometimes people call this carrying because you see five plus seven is twelve you write the 2 in the ones place and you write the 1 in the tens place 12 is one - let me make it very clear five plus seven is equal to is equal to twelve and all we did is we wrote the one here we wrote that in the tens place we wrote it up here so that's what it kind of looks like you are carrying it you're putting it at a higher place but you're just writing this in the tens place and we're up here was just an easy place to do it but remember all we did all we did there as we said look we have five we have seven that would be 12 we can't write a 12 in the ones place so let's take ten of those 12 and regroup them as a 10 and then we have the 2 left over here but an easier way to think about it is 5 plus 7 is 12 1 2 and now we can add the tens place we have 110 plus 3 tens plus two tens well what's that going to be well that's going to be six tens one plus three plus two is six let's do that so we have whoops Wow that was that's not what I wanted to do let me and that was kind of all right we have we have one we have two we have three and we have four and we have my computer slowing down 5.if and then we have and then we have six six tens six tens and so what is that what does that leave us with one plus three plus two tens it's going to be six ten 35 plus 27 is 62 35 plus 27 is six tens and two ones 62