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# Regrouping to add 1-digit number

## Video transcript

so we have the number 35 the three is in the tens place so it represents 30 or three tens 110 two groups of ten three groups of ten and then the five is in the ones place so it represents five ones we see them right over here one two three four five now we want to take that 35 or those three tens and five ones and add six six ones the six is in the ones place one two three four five six ones and I encourage you to pause the video and try to do that add 35 to 6 so let's think about it now so I'm going to start with the ones so I have five ones and I want to add six ones so what's that going to be what's that going to be all together well five ones plus six ones that's going to be eleven once and I still have three tens so we could say it's going to be three tens three tens and eleven ones three tens I could write plus eleven ones here now this is a little bit of a problem because we can't write a two-digit number in the ones place or in any one of the places I can't this number is it going to be 311 it's going to be three tens and 11 ones but how can i rewrite this or how can i regroup things so that I do I only have a single digit number here I have zero one two three four five six seven eight or nine here instead of a two-digit number the one one well I can regroup I could say look I have enough ones here to create a group of ten I could take ten of them so let's take these ten right over here and put them together and make a new group of ten so a new group of ten right over there so if I take so just to be clear what I just did I just took these ten these ten ones and I stuck them together and I turned it into this new group of this new group of ten so now what do we have so when you regroup like this you see that you have one two three four tens four tens and how many ones do you have now four tens plus well I've regrouped all of these ten ones and all I have left is this this one one right over there so I could write this as four tens plus one one once again three tens and eleven ones that's the same thing as four tens and one one and so we can write that over here we can write this as we can write this as 1 1 and for tens and for tens now how could you get this if you weren't if you didn't do it like this and drawing everything out and regrouping like this and this is actually what you should be doing in your head but another way of thinking about it you could say all right five plus six that's going to be eleven ones but I can't write an eleven here in the ones place so I could say that's going to be the same thing as 1/10 plus one one one 10 plus one one sometimes it's taught that 5 plus 6 is 11 carry the 1 but really what you're doing is you're saying 5 plus 6 is 1 10 plus 1 1 and in fact an 11 the number 11 right over here so if I write the number 11 the number 11 has a 1 in the tens place and a 1 in the ones place so it's 110 plus 1 1 so you're just saying that 5 plus 6 is 11 which is the same thing as 110 and 1 1 and then you add your tents together 110 plus another 3 tens is going to be is going to be 4 tens but I really want you to appreciate what's going on you're not just blindly saying oh 5 plus 6 is 11 so I'm going to write one of the ones here and write the 1 in the tens place here you're doing it because you're regrouping you're regrouping that that group of 10 you're saying hey I could take 10 of these ones and I can turn them into a new group of 10 and that would just leave me one in the ones place one in the loved ones place and I've just turned all the other ones into a new group of 10