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so this right over here is one way to represent the number 37 the number 37 has a three right over here in the tens place and so this three literally represents three tens notice this is a ten here this is a ten here and this is a ten here three tens or thirty and you see each of these tens there's one two three four five six seven eight nine ten now the seven is in the ones place it literally represents seven ones and you see that right over here one two three four five six seven so you can say that 37 37 is equal to is equal to three tens do this in the purple color it's equal to three tens plus plus seven ones plus seven ones now what if I wanted to add something to 37 what would 37 37 37 plus plus to be equal to how many tens and how many ones well think about it we're now going to add two so we're adding two ones so we're going to add one and two so now we still have three tens so let's write that down so we still have three tens but now we have a different number of ones we now have one two three four five six seven eight nine we now have nine ones or another way to think about it seven ones plus two ones is nine ones so let me write that down so plus nine ones or another way to think about it is 37 30 let me do this right the same way 37 37 plus two is equal to three tens so I could write this as 30 and then nine ones is equal to 39 and that's exactly what we have here we have 30 this is the three tens and then we have nine ones which is 39 39 squares