Video Transcript
Complete 1000 multiplied by seven equals something multiplied by 1000.
To solve this problem, we’re actually gonna use something which is called the commutative property of multiplication. But what does that actually mean? Well, the word commutative actually comes from the word commute, which means to move around. And what the commutative property of multiplication tells us is that if we have 𝑎𝑏, it’s equal to, it’s the same as 𝑏𝑎. So what that actually means is if we move around the numbers that we’re actually multiplying, it won’t affect it.
So it doesn’t matter if it’s 𝑎 then 𝑏, so 𝑎 multiplied by 𝑏 or 𝑏 multiplied by 𝑎. We’re gonna get the same answer. Now if we look back at our original question, what I’ve done is actuallty labelled it in the same way that we’ve actually got our commutative property of multiplication.
We can see that our 𝑎 would be equal to 1000 and our 𝑏 would be equal to seven. So therefore, if we then substitute in for the missing 𝑏, we’d have 1000 multiplied by seven equals seven multiplied by 1000. So we can say that our missing value is seven. And we can just double-check this. We’ve got 1000 multiplied by seven. So yes, that’s 7000. And that’s equal to seven multiplied by 1000. So yes, great! Seven is definitely the missing number.