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# Understanding place value when adding ones

Sal adds 37 + 2 by thinking about place value.

## Want to join the conversation?

- what if their was a way to divide any thing by0(11 votes)
- Imagine you're having a sleepover. You have 10 friends with you. The pizza delivery guy got distracted and didn't deliver, and you have no pizza. You can't divide the pizza that you don't have by the 10 friends that you do have. This means nobody gets pizza and everybody is sad. Nobody gets pizza because, there is no pizza and you can't divide 0 by 10.(17 votes)

- I am curious, but who came out with the term place value?(6 votes)
- Sorry for the late response, but, I think scientists came up with it? I'm not sure.(2 votes)

- why is it called place value like h t u(3 votes)
- as seen at0:39tens as 3 or t(*10) 7 as ones or u(units) and the hundreds as h or(*100)(2 votes)

- Is there another way to understand place value?(2 votes)
- Yes, There is a lot of ways to understand place value but the salman khan explanation is way better than others so try watching again if you don't get what he mean(2 votes)

- This looks hard but FUN! (:(3 votes)
- when he said 37 = 3tens + 7ones why didn't he put a different way for adding so we can learn something new?(2 votes)
- tens = 10 and 3 is just 3, so Multiply 10*3 = 30 and ones is just 7. So add them all 30 +7 = 37. also you can search it up on google or on khan academy's search bar if you want to know some stragies for adding(2 votes)

- can you dvide it into 2(2 votes)
- what is 5 times 10(0 votes)
- You add 10 five times or 5 ten times. It's 10+10+10+10+10 or 5+5+5+5+5+5+5+5+5+5, both equals 50.(2 votes)

- who made place value, and why?(1 vote)
- We count using Arabic numerals in a base 10 system.

If you know it, try doing a complicated addition problem in Roman numerals. Without base 10, you might find it significantly harder.(3 votes)

## Video transcript

- 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. 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 30. 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. You see that right over here,
one, two, three, four, five, six, seven, so you can say that 37 is equal to three tens, do this in the purple color,
is equal to three tens plus seven ones. Now, what if I wanted
to add something to 37? What would 37 plus two be equal to? How many tens and how many ones? Well, let's 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. Another way to think about it is 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, let me just write it the same way, 37 plus 2 is equal to three tens, so I can write this as 30 and then nine ones, is equal to 39, and that's exactly what we have here. We have 30, this was the three tens, and then we have nine
ones, which is 39 squares.