Multiplying fractions by whole numbers on a number line
Sal multipiies fractions by whole numbers using the number line.
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- Why does he make the question 5x1/3 so complex when all you have to do is do 1x5=5 and add the 3?(25 votes)
- "All you have to do" shows that the problem is already intuitive for you to solve. For those where the problem is not yet intuitive to solve, it needs to be explained why the solution works.
Someone is eventually going to ask you "Why do I have to do 1x5 and why is 1x5=5?" and you have to be able to explain that in a clear manner.(9 votes)
- My goal is 1000000 upvotes.So let's start clicking upvotes!(15 votes)
- what if the number is big this is hard! Help Me...(12 votes)
- so you know that 3 = 3/1 right. so if 10 = 10/1 and you had a problem that said 10 x 5/10 it would = 10/1 x 5/10 10 x 5 = 50 and 1 x 10 = 10 so it would be 50/10 or 5. pls, vote me up!(5 votes)
- Is this hard for you guys?(10 votes)
- Can I get likes for a badge?(9 votes)
- Why do we have to mutiply fraction?(5 votes)
- because u need it in life even tho u really want need it unless you want to be something(0 votes)
- Yes, I understand this, but why would we want to multiply fractions? We could convert them into decimals and easily solve them. So why multiplying fractions?(5 votes)
- It may not seem useful now, but later on you will have algebraic expressions with uknown numbers (x, y, ...) in fractions and in some cases it will be very difficult to write such numbers as decimal values.(2 votes)
- upvote mwe pwease!i awm aiming for won hundwed vovtes i pwomise I pwpbawy wont pwank ywou!and wook! i hawve awl cowwect gwamar(5 votes)
- why do you have to multiply upper one to upper one and the low one to low one(6 votes)
We're asked to move the orange dot to the number that equals five times 1/3. Alright, so one way to think about it, we just have to move 1/3 five times. So let's do it once, so that's going to be 1/3, you do it twice, you get to 2/3, you do it three times, you get to 3/3, four times, you get to 4/3, five times, you get to 5/3. Five times 1/3 is gonna be 5/3. Or you could say five 1/3, which is the same thing as 5/3, hopefully that makes some sense. Let's do some more examples here. So let's say we need to figure out, so let's see, it says move the orange dot to the number that equals two times 4/3. Alright, so one times 4/3 is just gonna get us to 4/3, and then if we have another 4/3, we're gonna add 4/3 to that, so we're gonna move another 4/3 to the right. So 4/3 plus 4/3 would get us to 8/3. 8/3, I'm having trouble moving this, 8/3. So one times 4/3 is just 4/3, and then two times 4/3 is 8/3. And notice that's the same thing as two times four, which is eight, over three, 8/3. Let's do one more of these. So, move the orange dot to the number that equals three times 3/2. So this is gonna be 0/2, that's just zero, so you could do that a zero times 3/2. One times 3/2, well that will just get us to 3/2. Two times 3/2, we'll add another 3/2, so that'll get us to 6/2. And then three times 3/2, we'll add another 3/2, that gets us to 9/2, and we're done.