If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Multiplication as repeated addition

Let's explore the idea of multiplication being the same as repeated addition. It shows how to express multiplication problems using repeated addition and highlights that multiplication is commutative, meaning the order of the numbers doesn't change the outcome.

Want to join the conversation?

  • old spice man blue style avatar for user Angry Johnny Boy
    ⣰⣾⣿⣿⣿⠿⠿⢿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷ ⣿⣿⣿⡿⠋⠄⡀⣿⣿⣿⣿⣿⣿⣿⣿⠿⠛⠋⣉⣉⣉⡉⠙⠻⣿⣿ ⣿⣿⣿⣇⠔⠈⣿⣿⣿⣿⣿⡿⠛⢉⣤⣶⣾⣿⣿⣿⣿⣿⣿⣦⡀⠹ ⣿⣿⠃⠄⢠⣾⣿⣿⣿⠟⢁⣠⣾⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⡄ ⣿⣿⣿⣿⣿⣿⣿⠟⢁⣴⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷ ⣿⣿⣿⣿⣿⡟⠁⣴⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿ ⣿⣿⣿⣿⠋⢠⣾⣿⣿⣿⣿⣿⣿⡿⠿⠿⠿⠿⣿⣿⣿⣿⣿⣿⣿⣿ ⣿⣿⡿⠁⣰⣿⣿⣿⣿⣿⣿⣿⣿⠗⠄⠄⠄⠄⣿⣿⣿⣿⣿⣿⣿⡟ ⣿⡿⠁⣼⣿⣿⣿⣿⣿⣿⡿⠋⠄⠄⠄⣠⣄⢰⣿⣿⣿⣿⣿⣿⣿⠃ ⡿⠁⣼⣿⣿⣿⣿⣿⣿⣿⡇⠄⢀⡴⠚⢿⣿⣿⣿⣿⣿⣿⣿⣿⡏⢠ ⠃⢰⣿⣿⣿⣿⣿⣿⡿⣿⣿⠴⠋⠄⠄⢸⣿⣿⣿⣿⣿⣿⣿⡟⢀⣾ ⢀⣿⣿⣿⣿⣿⣿⣿⠃⠈⠁⠄⠄⢀⣴⣿⣿⣿⣿⣿⣿⣿⡟⢀⣾⣿ ⢸⣿⣿⣿⣿⣿⣿⣿⠄⠄⠄⠄⢶⣿⣿⣿⣿⣿⣿⣿⣿⠏⢀⣾⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣷⣶⣶⣶⣶⣶⣿⣿⣿⣿⣿⣿⣿⠋⣠⣿⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⠟⢁⣼⣿⣿⣿⣿⣿ ⢻⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⠟⢁⣴⣿⣿⣿⣿⣿⣿⣿ ⠈⢿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⡿⠟⢁⣴⣿⣿⣿⣿⠗⠄⠄⣿⣿ ⣆⠈⠻⢿⣿⣿⣿⣿⣿⣿⠿⠛⣉⣤⣾⣿⣿⣿⣿⣿⣇⠠⠺⣷⣿⣿ ⣿⣿⣦⣄⣈⣉⣉⣉⣡⣤⣶⣿⣿⣿⣿⣿⣿⣿⣿⠉⠁⣀⣼⣿⣿⣿ ⠻⢿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣶⣶⣾⣿⣿⡿⠟
    Upvote if you like un0
    (18 votes)
    Default Khan Academy avatar avatar for user
  • duskpin ultimate style avatar for user JacksonD
    upvote if you think Sal is smart.
    (14 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user jesusduran0031
    what is 1000000+2000000=
    (10 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user Chikemdi Onuoha
    you cant skip by 102,S
    (6 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user h.zetian
    This is a good explanation of repeated addition. I personally think that if the teacher teaching us could make the lessons funnier it would make more children willing to listen.
    (8 votes)
    Default Khan Academy avatar avatar for user
  • starky seedling style avatar for user jsloyoperez
    ⣰⣾⣿⣿⣿⠿⠿⢿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷ ⣿⣿⣿⡿⠋⠄⡀⣿⣿⣿⣿⣿⣿⣿⣿⠿⠛⠋⣉⣉⣉⡉⠙⠻⣿⣿ ⣿⣿⣿⣇⠔⠈⣿⣿⣿⣿⣿⡿⠛⢉⣤⣶⣾⣿⣿⣿⣿⣿⣿⣦⡀⠹ ⣿⣿⠃⠄⢠⣾⣿⣿⣿⠟⢁⣠⣾⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⡄ ⣿⣿⣿⣿⣿⣿⣿⠟⢁⣴⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷ ⣿⣿⣿⣿⣿⡟⠁⣴⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿ ⣿⣿⣿⣿⠋⢠⣾⣿⣿⣿⣿⣿⣿⡿⠿⠿⠿⠿⣿⣿⣿⣿⣿⣿⣿⣿ ⣿⣿⡿⠁⣰⣿⣿⣿⣿⣿⣿⣿⣿⠗⠄⠄⠄⠄⣿⣿⣿⣿⣿⣿⣿⡟ ⣿⡿⠁⣼⣿⣿⣿⣿⣿⣿⡿⠋⠄⠄⠄⣠⣄⢰⣿⣿⣿⣿⣿⣿⣿⠃ ⡿⠁⣼⣿⣿⣿⣿⣿⣿⣿⡇⠄⢀⡴⠚⢿⣿⣿⣿⣿⣿⣿⣿⣿⡏⢠ ⠃⢰⣿⣿⣿⣿⣿⣿⡿⣿⣿⠴⠋⠄⠄⢸⣿⣿⣿⣿⣿⣿⣿⡟⢀⣾ ⢀⣿⣿⣿⣿⣿⣿⣿⠃⠈⠁⠄⠄⢀⣴⣿⣿⣿⣿⣿⣿⣿⡟⢀⣾⣿ ⢸⣿⣿⣿⣿⣿⣿⣿⠄⠄⠄⠄⢶⣿⣿⣿⣿⣿⣿⣿⣿⠏⢀⣾⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣷⣶⣶⣶⣶⣶⣿⣿⣿⣿⣿⣿⣿⠋⣠⣿⣿⣿⣿ ⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⠟⢁⣼⣿⣿⣿⣿⣿ ⢻⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⠟⢁⣴⣿⣿⣿⣿⣿⣿⣿ ⠈⢿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⡿⠟⢁⣴⣿⣿⣿⣿⠗⠄⠄⣿⣿ ⣆⠈⠻⢿⣿⣿⣿⣿⣿⣿⠿⠛⣉⣤⣾⣿⣿⣿⣿⣿⣇⠠⠺⣷⣿⣿ ⣿⣿⣦⣄⣈⣉⣉⣉⣡⣤⣶⣿⣿⣿⣿⣿⣿⣿⣿⠉⠁⣀⣼⣿⣿⣿ ⠻⢿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣶⣶⣾⣿⣿⡿⠟ wow
    (7 votes)
    Default Khan Academy avatar avatar for user
  • piceratops tree style avatar for user Horse queen
    why is the times sign a x thingy
    (7 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user Julia Bell
    3000 + 3000= 6000 ...
    (5 votes)
    Default Khan Academy avatar avatar for user
  • piceratops ultimate style avatar for user 𝓜𝓪𝓱𝓮𝓼𝓱 𝓜𝓪𝓱𝓮𝓷𝓭𝓻𝓪𝓴𝓪𝓻
    At , Sal was saying that "you can view multiplication as repeated addition." so is multiplication just reapeated addition?
    (4 votes)
    Default Khan Academy avatar avatar for user
  • aqualine ultimate style avatar for user dragonlovers
    whats peporoni?
    (3 votes)
    Default Khan Academy avatar avatar for user

Video transcript

- [Instructor] So as some of you already know, I really enjoy eating a good avocado, which, despite its appearance that it looks like a vegetable, but it's actually a fruit. And let's say that I eat two avocados per day, and I eat two avocados per day for six days. Now, there's a couple of ways that I could think about how many avocados did I eat? I could say, hey, I eat two a day, and I'm going to do that for six days, so I'm gonna add six twos together. So it'll be two, plus two, plus two, plus two, plus two, plus two, I have six twos right over there. And then I can add them together. And we could say two plus two is four. You add another two, you get to six. You add another two, you get to eight. Yet another two to get to 10. Yet another two, you get to 12. And that all is fine, but there's an easier way to express this repeated addition. One way is to view it as multiplication. Instead of just writing out six twos and adding them together, mathematicians have come up with a neater way of writing that. Let's say, okay, we're going to add up a bunch of twos. How many twos are we going to add up? We're going to have six of those twos, and we need to come up with some type of a symbol for it. So we will use this X-looking thing. And so, six times two can be viewed as repeated addition in exactly this same way. So six times two would be equal to 12. And we could go the other way around. If someone were to ask you, what is four times three? Pause this video and see if you can write it out as repeated addition, like we saw up here. Well, one way to interpret this is to say, this is four threes, so we could say this is equal to three, plus three, plus three, plus three. And three plus three is six, six plus three is nine, nine plus three is equal to 12. You might be familiar with skip counting, and you would say three, six, nine, 12. Just out of curiosity, what do you think three times four is going to be? Pause this video and try to represent it as repeated addition, and then see what you come up with. Well, we can interpret this as three fours. And so, we could say this is going to be four, plus four, plus four. And if we skip count fours, we'd have four, eight, 12, (chuckles) I was about to go to 16, four, eight, 12. So this is going to be 12. So this is interesting, at least for this example, for these two examples, I got to the same thing. Four times three got me the same result as three times four, interesting. I wonder if that's always true. But anyway, big picture from this video is that you can view multiplication as repeated addition.