Decomposing hundredths on number line

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About this video

This video works through a Khan Academy exercise: 26/100 = star/10 + 6/100, using a number line. Each tenth is split into 10 hundredths, so the 20 hundredths shown by the magenta arrow equal 2 tenths, and the star is 2.

You'll be able to

  • explain that a hundredth is one tenth of a tenth.
  • use a number line to break hundredths into tenths and hundredths.
  • complete equations like 26/100 = ?/10 + 6/100.

Key words

tenth
One of 10 equal parts of a whole.
hundredth
One of 100 equal parts of a whole; it is one tenth of a tenth.
number line
A line with evenly spaced marks that shows numbers in order.
Transcript

- [Voiceover] So we have an example exercise from our Khan Academy exercises. This is the decomposed fractions. with denominators of 100. Use the following number line to complete the equation. The equation says 26-hundredths is equal to star-tenths plus six-hundredths.

And they give us this number line and on this number line-- Let's see, this is zero right over here, zero-tenths, which is the same thing as zero, and it goes all the way to 26-hundredths. Let's see if that makes sense. Well, you see between zero-tenth and one-tenth, they split into 10 equal sections.

One, two, three, four, five, six, seven, eight, nine, 10. So if you divide a tenth into tenths, each of these is going to be 100. A hundredth is one-tenth of a tenth. So that's 100, 200, 300, 400, five, six, seven, eight, nine, 10-hundredths, 11, 12, 13, 14, 15, 16, 17, 18, 19 20-hundredths.

21, 22, 23, 24, 25, 26-hundredths. So that's exactly what they wrote there. So they say 26-hundredths, which is this thing right over here, is equal to star-tenths, which is really what's being depicted in magenta, plus six-hundredths. The six-hundredths is this green right over here.

Adding the six-hundredths. Adding one, two, three, four, five, six-hundredths. So what is this right over here? This magenta or this pink arrow? Well we could say that's 20-hundredths. If you count it that's 10, 20-hundredths. Or, you could see, well that's just two-tenths.

So 26-hundredths is the same thing as two-tenths plus six-hundredths. And it gets you right over there. So this right over here is going to be two-tenths.

Video © Khan Academy, used under CC BY-NC-SA. Watch on Khan Academy. Puzzicle is not affiliated with Khan Academy.