Using multiplication strategies to find products
About this video
The video finds 8 x 6 using a partly completed multiplication table. It shows three strategies: doubling 4 x 6 = 24 to get 48, counting on by 8 down the 8s column, and counting on by 6 down the 6s column. It also notes that 8 x 6 and 6 x 8 have the same answer.
You'll be able to
- find 8 x 6 = 48 by doubling 4 x 6.
- use patterns in a multiplication table column to find a product.
- explain why 8 x 6 and 6 x 8 have the same answer.
Key words
- multiplication table
- A grid that shows the answers to multiplication facts in rows and columns.
- product
- The answer you get when you multiply numbers.
- multiple
- A number you get by multiplying a number by 1, 2, 3 and so on, like 8, 16, 24.
Transcript
- [Instructor] We're told here is a partially completed multiplication table, and we can see they go all the way up to the 4 times tables, I guess you could call it that. And they want us to figure out what 8 times 6 is, so pause this video, have a go at that before we do this together.
Okay, so let's think about where 8 times 6 is on this multiplication table. So if we say 6 times 8, it is over here, because we know that 8 times 6 is the same thing as 6 times 8. Or we could think about 8 times 6 exactly as it's written here, which I would say is this square right over here.
So what are ways that we could figure out what goes in these? And the same numbers should go into both of these. Well, one way is to look right over here where they tell us what 4 times 6 is. We see that 4 times 6 is equal to 24. So based on that, we could say 8 times 6 is going to be twice as much as that.
So if we multiply this by 2, or another way to think about it, if we added another 24 over here, we're going to get to 8 times 6. So 24 plus 24, you might recognize as being equal to 48. So that's one way you could have done that. You could have said that is 48.
Another way that you could have approached this is you could have tried to fill this one in and you could have said, "okay, if we're going down this column, every time we go down one, we're increasing by 8 'cause we're going larger and larger multiples of 8. So 8 times 5, we would add 8 again, we would get to 40, and then if we add 8 another time, we would get to 48."
So these are all ways to do it. You could also go down this column right over here and add 6 every time. And you could see that that would work. If you add 6 to 24, you'd get 30. Add 6 to that, you get 36. Add 6 to that, 42. Add 6 to that, you get to 48.
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