• 2 months ago
Transcript
00:00Hey kids, thanks for joining me today. I am here at the number line fraction race with
00:06my friend Mr. Robot. We are racing each other. While we do a few practice runs, can you guys
00:12learn about fractions on a number line? Great! Ok Mr. Robot, on your mark, get set, go! Hey!
00:20I didn't say go yet! To start off, let's review some concepts about fractions.
00:28Here we have a fraction of one fourth. A fraction is a part of a whole or a part of a group.
00:34The numerator is the number on top and shows the parts we are talking about. In this case
00:39it is the one green part of the circle. The number on the bottom is the denominator. The
00:45denominator tells you how many equal parts there are in all. This circle has four equal
00:50parts, so the denominator is four. One fourth of the circle is colored green. Here is a
00:58number line. A number line is pretty easy to draw and you will soon see that they can
01:03look a lot like a ruler or a tape measure. Up top we have the fraction we need to represent
01:08on the number line. We need to divide the line into the correct number of pieces. The
01:14denominator tells us the total amount of pieces. What is the denominator in our fraction?
01:21The four is the denominator, so we need to divide this into four pieces. The zero marks
01:27the start of the number line. We start at zero. The number one is on the far right.
01:34Why do you think there is a one there? The one represents the one whole or all four pieces
01:39of the fraction above. We could also say that it is four fourths. Four fourths is the
01:47same or equal to one, so that is why we have the one here to show we have reached one whole
01:53on the number line. This number line is broken into four equal parts. From here to here is
02:02one fourth. From here to here we have two parts which is two fourths. From here to here
02:09we have three parts or three fourths. From here to here we have four parts or all of
02:16them which is four fourths or one like we just talked about. Something very important
02:23we need to remember is when we are counting the fractions on a number line, we are not
02:27counting the lines. We are counting the parts in between. The jumps we did with the curved
02:33lines shows the parts of the fraction. We now know where one fourth is on the number
02:38line. It is this part right here. That was great. Let's look at a problem to see if we
02:45can solve it. The problem says what fraction is shown on the number line. One way to start
02:53this is by finding the denominator in the fraction. Remember the denominator is the
02:57total amount of parts and in order to find that we need to count all the parts. We start
03:04at zero and count one, two, three, four, five, six, seven, eight. We counted eight parts.
03:19All that is left to do is count the parts up to the green star. Counting again we count
03:25one, two, three, four, five, six, seven. We have both the numerator and the denominator
03:36and the fraction shown is seven eighths. Great job guys. Let's take a look at another problem
03:42to see how we do. The problem says what fraction is missing. In this problem we know a lot
03:50of things already. We know the denominator is five so that means there are five total
03:55parts. You may have figured it out already but let's count each part on the number line
03:59to find the missing fraction. We count one fifth, two fifths, three fifths, four fifths.
04:09We have gotten to the missing fraction. What is it? Four fifths. The missing fraction is
04:16four fifths. Amazing. We have one last one to do which will require you to draw your
04:21own number line. The problem says using this model draw the fraction on a number line.
04:29Take a minute and draw this fraction on a number line then we will go over it together.
04:35Did you get it? Let's do it together. We have the start to our number line. The zero
04:41is where we start and we have one at the end because we are talking about just one whole
04:46shape. The denominator is what tells us how many total parts there are. If we count each
04:51part of the rectangle we see there are four total parts so we divide the number line into
04:56four parts. Looking at the rectangle two parts are colored green so that is our numerator.
05:04We start counting one, two. We now have reached the two on the number line. The fraction is
05:11two fourths. We have shown where two fourths is on a number line. Great job. Another cool
05:18fact is you can notice that two fourths is half way between zero and one which tells
05:23us two fourths is the same as one half. Awesome. I am going to win Mr. Robot. I just need to
05:32get a little faster. Okay, maybe I will win next time Mr. Robot. See you guys later. Goodbye.