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let's count together from 0 to 19 oh you have 0 1 2 3 4 5 6 7 8 9 and now we go to the two-digit numbers and then we go to 10 11 12 13 14 15 16 17 18 and 19 now why did I do this well the whole point of this is to see a pattern here especially in these two-digit numbers what do we see is true about all of these numbers that are you could think of them they're being in their teens well they all you might see have a 1 as their first digit and that one is sitting in what we will call the tens place and Lori says that each of these numbers that one represents a 10 what do I mean by that well if we go up to 10 over here this is telling us that this one it represents 10 and then this is zero represents zero ones so 10 is 10 plus zero you say oh well what's the big deal we already knew that any number plus zero is that number again but I think you'll see the pattern as we go into these other numbers so 11 is equal to so this one the yellow one represents 10 and then this pink one represents 1 and then 12 12 this yellow one represents 10 and then this pink 2 represents 2 or you could rub you could think of it as this yellow one says this is one 10 so we have a 10 right over there and this is two ones and you have 2 right over there and we can keep going I think you see the pattern 13 is 10 plus 3 13 is 10 plus 3 14 is equal to 10 plus 4 plus 4 15 is equal to 10 plus 5 and encourage you to pause the video now and try to finish the rest try to write 16 17 18 and 19 as ten plus some other number and really just make sure that you understand the pattern that's happening so let's do that so 16 so I can even write them all like this they're all going to be ten ten plus something so 16 is ten plus six seventeen is ten plus seven 18 is ten plus eight and 19 is 10 plus nine and when you write it out like this it becomes pretty clear that this one in each of these numbers represents ten and then the digit on the right that just represents that many ones