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### Course: 4th grade > Unit 8

Lesson 5: Adding and subtracting mixed numbers- Adding mixed numbers with like denominators
- Subtracting mixed numbers with like denominators
- Add and subtract mixed numbers (no regrouping)
- Mixed number addition with regrouping
- Subtracting mixed numbers with regrouping
- Add and subtract mixed numbers (with regrouping)

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# Adding mixed numbers with like denominators

Sal practices adding mixed numbers with common (like) denominators.

## Want to join the conversation?

- I love doing khan academy it helps a lot!(24 votes)
- How do u turn 100/16 to an improper fraction(8 votes)
- Hi there, since an Improper Fraction is when a numerator (top number: in this case 100) is greater/larger than the denominator (bottom number: n this case 16), it is already an Improper Fraction: 100/16.(5 votes)

- I don’t understand how to get the whole number, can you help me out?(10 votes)
- I know what you mean(0 votes)

- i like khan acadamy so much(7 votes)
- Khan academy is so fun and easy 10/10😍(6 votes)
- What we're going to do in this video is to start thinking about adding mixed numbers. Now just as a reminder of what a mixed number is, it'd be something like three and 2/8. It's called mixed because part of the way we represent this number is there's a whole number, the three, and then part is as a fraction, 2/8. But the numbers three and 2/8ths. So let's think about how we might be able to add three and 2/8ths to five and 3/8ths. So pause this video and see if you can have a go at this before we work through this together. All right, now let's work through this together. Now there's a couple of ways that we could approach this. You might recognize that three and 2/8ths is the same thing as three plus 2/8ths, and five and 3/8ths is the same thing as five plus 3/8ths. And so if we add these two things together we're just adding really these four things together and the order in which we add doesn't matter so you could view this as three plus five plus 2/8ths plus 2/8ths, plus 3/8ths, notice it's just the same thing, I'm just changing the order with which we are adding, and now what is three plus five? Three wholes plus five wholes, we'll that's just going to be eight. And then what is 2/8ths plus 3/8ths? Well if I have two of something, in this case eighths, and I add three more of that something, in this case eighths, I'm gonna have five of that something, in this case 5/8ths. So this is going to be eight plus 5/8ths. Which we can express as a mixed number as just being equal to eight and 5/8ths. Now there's other ways that you might see folks approaching this. You might see something like this where people will write three plus 2/8ths and then they will write right below that they'll write the five in the ones place, or in the whole number and there's only a ones place in these whole numbers, so you'd write the five right below the three and then plus and then the fraction you'd write right below the fraction. 3/8ths. And then we can add vertically like this where first we can look at the fractional part, 2/8ths plus 3/8ths is going to be equal to 5/8ths and then three plus five is going to be equal to eight and if you add these two together, eight and 5/8ths, you get eight and 5/8s. So different ways to approach it, but that will hopefully start to get you comfortable with adding a mixed numbers.(4 votes)
- i cant read this to overweming(3 votes)

- Can you do, 3 2/8 + 5 3/8

26 + 43= 89

Can we do like this(3 votes)- If you changed the mixed fraction to improper, then removed the denominator, yes. But then you have to convert the 89/8 back to a mixed fraction.(4 votes)

- I liked the comment though(4 votes)
- can u make this video a little bit more clear plzz and thank u !(3 votes)
- the whole numbers are basicly fractions right ?? like 8/8 is equal to one ?(2 votes)
- yes. anything with the numerator and denominator being the same is equal to 1.

edit: say you have 28/30 + 2/30. it equals 30/30. 30/30 is 1.(2 votes)

## Video transcript

- [Instructor] What we're
going to do in this video is to start thinking about
adding mixed numbers. Now just as a reminder of
what a mixed number is, it'd be something like three and 2/8. It's called mixed because part of the way we represent this number
is there's a whole number, the three, and then part
is as a fraction, 2/8. But the numbers three and 2/8ths. So let's think about how
we might be able to add three and 2/8ths to five and 3/8ths. So pause this video and see
if you can have a go at this before we work through this together. All right, now let's work
through this together. Now there's a couple of ways
that we could approach this. You might recognize that three
and 2/8ths is the same thing as three plus 2/8ths, and five and 3/8ths is the same thing as five plus 3/8ths. And so if we add these two things together we're just adding really
these four things together and the order in which
we add doesn't matter so you could view this as three plus five plus 2/8ths plus 2/8ths, plus 3/8ths, notice it's just the same thing, I'm just changing the order with which we are adding, and now
what is three plus five? Three wholes plus five wholes, we'll that's just going to be eight. And then what is 2/8ths plus 3/8ths? Well if I have two of
something, in this case eighths, and I add three more of that something, in this case eighths, I'm gonna have five of that something, in this case 5/8ths. So this is going to be eight plus 5/8ths. Which we can express as a mixed number as just being equal to eight and 5/8ths. Now there's other ways that you might see folks approaching this. You might see something like this where people will write three plus 2/8ths and then they will write right below that they'll write the five in the ones place, or in the whole number and
there's only a ones place in these whole numbers,
so you'd write the five right below the three and then plus and then the fraction you'd
write right below the fraction. 3/8ths. And then we can add vertically like this where first we can look
at the fractional part, 2/8ths plus 3/8ths is
going to be equal to 5/8ths and then three plus five is
going to be equal to eight and if you add these two together, eight and 5/8ths, you get eight and 5/8s. So different ways to approach it, but that will hopefully
start to get you comfortable with adding a mixed numbers.