Multiplying: 2-digit by 1-digit (regrouping)

Let's try to compute 6 times 37. And I'll show you one way of doing this. And then in future videos, we can look at other ways of doing this and think about why this is actually working. So what I like to do-- and this is often called the standard method-- is take the larger of the two numbers. It doesn't matter if you're doing 6 times 37 or 37 times 6. They equal each other. 6 times 37 is the same thing as 37 times 6. So what I like to do is I take the larger of the two numbers, and I write it on top. So I'll write 37. And then the smaller of the two numbers, which is 6, I'll write it on the bottom. And I'll align it by the correct place. This only has one digit. It's in the ones place, obviously. So I can write the 6 right over here. And I'll write the multiplication symbol like that. And this is just another way of expressing 37 times 6, which is the same thing as 6 times 37. Now, what we do is we go with this, the first place in this lower number. And there's only one place here. It's only the number 6 right over here. And we're going to multiply that times each of the digits up here. So first, we will start with 6 times 7. So we're going to first multiply 6 times 7. Well, you remember from your multiplication tables, 6 times 7 is equal to 42. Now, we don't just write 42 here. At least, not in the standard method we wouldn't write 42 here. We'd write the 2 in 42 in the ones place. So we'd write that right over there. And then we'd carry the 4 in 42 up to the tens place. Now we need to think about what 6 times 3 is. Well, once again, we know 6 times 3. 6 times 3 is equal to 18. But we can't just write an 18 down here. We still have this 4 to deal with. So 6 times 3 is 18, but we've got to then add the 4. So 6 times 3 is 18, plus 4 is 22. So it's 6 times 3, and then we're adding that 4 right over there. And that's how we get our answer-- so 222.