About this video
The video looks at how to say and write 20,000.507. It first breaks it into 20,000 + 5/10 + 0/100 + 7/1000. Then it rewrites 5/10 as 500/1000 so the decimal part combines into 507/1000, giving "20,000 and 507/1000".
You'll be able to
- break a decimal into whole number, tenths, hundredths and thousandths.
- rewrite tenths as thousandths by multiplying top and bottom by 100.
- write a decimal with thousandths in word form.
Key words
- thousandths
- Parts of a whole split into 1000 equal pieces; the third place after the decimal point.
- decompose
- Break a number into parts, such as each place value.
- equivalent fractions
- Fractions that have the same value, like 5/10 and 500/1000.
Transcript
So I'm going to write out a number that we're going to think about how we could say or actually write that number. So I'm just going to write it out. I'm going to resist the temptation to actually speak it out because that's normally how I operate. But I'm not going to do that right now.
So there's several ways that we can pronounce. So I encourage you to pause it and try to pronounce it, yourself. You might not even need to pause it. Well, the first thing that jumps out, well we've got 20,000 and then some. So maybe we should write it that way.
So we've got 20,000. 20-- actually let me write it out as numbers first to really decompose it. So we have 20,000. And then what do we have on top of that? Well we have 5/10. This is the tenths place. So we can literally write that as 5/10. 5/10. Then we have 0, 0/100.
I'll write that as a hundredths place just so that we can keep track of it. And then finally, we have 7/1000, that's the 1000th place. So we could write that, plus 7/1000. So if we would write down everything that I just spoke out loud, we would say that this is 20-- let me write that a little bit neater.
This is 20,000. 20,000 and 5/10. And 5-- let me write out the word-- and 5/10 and 7/1000. Now, this isn't the only way to say this. Another way of thinking about it is to try to merge the 5/10 and the 7/1000 in terms of thousandths. So let's think about this. So we could write this as-- so once again, we would have our 20,000.
But instead of 5/10 and 7/1000, let's write our 5/10 in terms of thousandths. And the easiest way to do it is to multiply the numerator and denominator, both here, by 100. So then we will have-- so this 5/10 is the same thing as 500 over 1,000. And the 7/1000 is still 7/1000.
And these two combined are 507/1000. So we could just call this 20,000 and 507/1000. so let's write that down. So we could just say this is 20,000 and 507/1000. This is 1/1000, while this right over here, 1,000, of course, actually represents 1,000. So we got 20 thousands, that's that right over there, and 507/1000.
Video © Khan Academy, used under CC BY-NC-SA. Watch on Khan Academy. Puzzicle is not affiliated with Khan Academy.