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Course: UP Class 6th (Bridge) > Unit 8
Lesson 1: Decimals on the number lineIdentifying hundredths on a number line
Lindsay identifies decimals graphed on a number line. Created by Lindsay Spears.
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- why can you never trust atoms? cause they make up everything!(32 votes)
- so if I had a fraction like 28/100 why would that convert as 0.28 as decimals. shouldn't the decimal have one hundred in it like the fraction?(13 votes)
- No, 8 is in the hundredths place, which is why the fraction is over 100.(8 votes)
- i would need help alot with this(8 votes)
- same this is hard(5 votes)
- at first i did not get fractions but now i do get it(7 votes)
- i feel old for using khan academy right now(7 votes)
- I don't understand what Lindsay means by 1.57, at2:33. Isn't the dot right at 1.50?(3 votes)
- So if you could subtract decimals how would you do it?(1 vote)
- You would subtract decimals like you would with whole numbers. So for example 8.87-3.25 you would do
8.87
-3.25
5.62(5 votes)
- okay I need Sul back! WE NEED SUL(3 votes)
- how do you now to add seven hundredths in the video(2 votes)
- The circle is in 7 on the line and seven hundredths you have to add it to 1.5 wich is 1.57(1 vote)
- I've got a want for math problems with food(1 vote)
Video transcript
- [Voiceover] Where is the
point on the number line? Here we have a number
line that starts at 1.5 or 1 5/10 and goes to 1 7/10. The distance between these
larger blue tick marks is 1/10 because we go
from 1 5/10 to 1 6/10, so that went up at 1/10
and then up to 1 7/10. This distance here is 1/10
or we could write that as 0.1 or as a fraction 1/10. That distance between each of these blue large tick marks is 1/10, but we want to know what is
this green point right here. To figure that out we also
need to figure out what do these black tick marks represent,
these smaller distances. From here to here is 1/10,
and within that 1/10th there are one, two,
three, four, five, six, seven, eight, nine, 10 equal spaces. Each of these little spaces
is 1/10 of this distance because it's one of the 10 equal spaces. This, right here, is 1/10th of this 1/10th because the large distance is 1/10th and this is 1/10 of that 1/10th. Another way we could say that is 1/100. 1/10th of 1/10th, if you
take 1/10 and divide it into 10 pieces, now you have 1/100. This distance is 1/100 which
means that each of these distances, this is another
1/100 and another 1/100, so how many 1/100 till
we get to our point? Let's see. 1/100, two, three, four, five, six, seven, 7/100 is what it took us to get there, so we could say 7/100, the
fraction or the decimal, 0.07 with a seven in the hundreds place. Looking at the whole number
line now, putting the whole thing together, we
started at 1.5 or 1 5/10, and we went another 7/100, so
we can write that as +7/100. We have 1 5/10 plus 7/100 which is a total of 1 57/100 or 1.57. Our point, right here, is at 1.57. 1 5/10 plus 7/100 gets us to 1 57/100.