Teach Long Multiplication For Two Digit By One Digit Multiplication

Hi, I'm Brooke. And in this video we'll be looking at how to use formal written method for solving multiplication problems. So in this problem, Joe has six decks of playing cards and each deck has 52 cards inside. And we need to find out how many cards does Joe have all together. So we can start by writing how many cards we've got in each deck, which is 52. And then we're going to multiply this by the number of decks that we have, which is six. So this method that we're going to do is called the expanded method. And this shows each step clearly. So first of all, I'm going to do 6 times 2. I'm just going to write this here. So 6 times 2 is 12. The next step is 6 times 5 tens. So I'm just going to write 6 times 5 tens here or 6 times 50. And 6 times 5 tens is 30 tens or 300. The final step is just to add the two together. So 12 add 300 equals 312. Now, once pupils are confident with this method, they can move on to a more compact method. So we're going to do 52 times 6 again, but this time pupils will need to be confident with regrouping. So I'm going to do six times two and that gives me 12 ones. So I'm going to put my two ones over here and I'm going to regroup it for 1 10. So you'll notice I'm putting the 10 into the tens column. I'm then going to do 6 times 5 tens, which is 30 tens. But then I need to remember to add back on the 1 10, which is 31 tens or 310. And you can see that Joe has 312 cards altogether. And that's how we multiply a two digit number by a one digit number.