Ordering decimals visually: least to greatest
Narrator writes 9/10 as '0.99' (should be 0.9); an on-screen note corrects it. One line is also garbled ('this first block year').
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Three students' project times are shown with grid models where each large square is one hour. Liam spent 9/10 of an hour, Ara spent 1 5/10 hours (1.5) and Vera spent 1 45/100 hours (1.45). Comparing wholes, then tenths, orders them from least to greatest: Liam, Vera, Ara.
You'll be able to
- read a tenths or hundredths grid model as a fraction and a decimal.
- compare decimals by looking at the wholes first, then the tenths.
- order decimals from least to greatest.
Key words
- tenths
- The 10 equal parts of a whole; 5/10 is written 0.5.
- hundredths
- The 100 equal parts of a whole; 45/100 is written 0.45.
- least to greatest
- Putting numbers in order starting with the smallest.
Transcript
- [Instructor] We're told the time in hours that three students spent on a project are represented below. Each large square represents one hour. Order the students by the time spent on the project from least to greatest. So pause this video and have a go at that before we do this together.
Alright, now let's do this together. So let's see who did the least. And this first block year, you could view that. Well actually, when we just visually look at it, we can immediately see that Ara and Vera did a whole hour, and then they did a little bit more, while Liam didn't even quite do a whole hour.
If we were to write the amount of time that Liam spent, it looks like this whole is divided into tenths. There's 10 equal rectangles, and nine of them are filled in. So this is 9/10. Oops, you can't see that. This is 9/10 of an hour, which is equal to, we could write it this way, 0.99.
So the least is Liam 'cause we're going, we're trying to go from least to greatest. So we've used Liam already. So now let's compare Ara or Ara and Vera. They both did a whole and then then some. So let's compare the then some. Ara did one, and then how many hours?
So it might be a little hard to see, but this is divided into tenths. There's 10 equal rectangles here. And if I look carefully, it looks like five of those 10 are colored in. So this is one and 5/10 of an hour, or hours I should say, which is the same thing as 1.5.
Well, if I look at Vera, it looks like we definitely have that one. We have that whole, and then here it looks like we have 10 hundreds completely filled in, 20 hundreds completely filled in, 30 hundreds, 40 hundreds, and then five more. So it looks like one and 45 over 100, which is the same thing as one and 45/100, or one and 4/10 and 5/100.
So if we were to compare between Vera and Ara, if we could just go to the tenths. Vera didn't get to 5/10. She's a little bit below 5/10. She's at 4/10 and then some. So Vera is the next smallest. So I will write Vera here, or I could say is also the next larger one than Liam.
And then the person who spent the most time studying, or on the project, that's what we're measuring, spent the most time on the project is Ara, an hour and a half. And we're done. We've used all of them.
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