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# Adding 1 vs. adding 10

CCSS.Math:

## Video transcript

so pause this video and real quick figure out what 27 plus one is and then if possible figure out what 27 plus 10 is alright so let's think it's think about it together so you might have been able to do this one pretty easily you might have said okay if I'm adding one it's just going to be the next highest number from 27 I would go to 28 if I have one more but the reason why I'm doing this exercise is we really think about place value so over here the number 27 we have a 2 in the tens place this is in the tens place right over here and then we have a 7 in the ones place so you could visualize the number 27 as two tens and I have two groups of 10 here and then seven ones and I have seven ones right over here and then if I add one more that's one more of these individual ones and so what am I going to be left with well I'm still going to have two tens I'm still going to have two tens but how many ones am I going to have now oh one two three four five six seven eight ones so it's going to be 28 so that might not be surprising for you but it's really valuable to think about in terms of place value because I'm going to be very useful later on as you learn more math now let's do the same thing with 27 plus 10 we already said the 27 that's two tens and 7 ones and now with 10 the one isn't in the ones place so it doesn't just represent one the one here is in the tens place so we have we have 110 and we have zero ones so we just have it the number 10 is just a group of just a group of 10 here so when you add these together what are you going to have well now you're going to have one two three tens so you're going to have three in the tens place and then you're still going to have you're still going to have one two three four five six seven ones seven ones so notice here when you add it a one you increase your ones place by one and here when you added 10 which is literally 110 you didn't increase the ones place you increased the tens place