Multiplying 3-Digit Numbers by 2-Digit Numbers | Math with Mr. J

Welcome to Math with Mr. J. In this video, I'm going to cover how to multiply a three-digit number by a two-digit number. We'll go through two examples together, and then I'll give you two practice problems that you can try on your own. Let's jump into number one where we have 154 * 26. Now, we'll start by setting this up. So, all we're going to be doing here is lining up the places. So, 154 times 26. So, the ones place is lined up, the four and the six. The 10's place is lined up, the five and the two, and then we have a one in the hundred's place. And now that we're set up, we're going to multiply. And really what we're going to be doing here is 154 * 6 and then 154 * 20. And I'm saying 20 because that two is in the 10 place. So it has a value of 20. Then we take those results and add them for our final answer. So we'll start with 6 * 4 here. That gives us 24. So we write our four and then carry the two. Then we do 6 * 5. That gives us 30 + that two is 32. Carry the 3. Then we have 6 * 1. That gives us 6 + that 3 is 9. 154 * 6 is 924. And now we are done with this six, done with this two, and done with this three. I like crossing numbers off when we are done with them. That way we don't confuse them with any other numbers later in the problem as we're working through. It helps us stay organized. Now, we need to do 154 * 20. So, we're moving over to that two in the 10 place. And since we're moving over to that two in the 10's place and we have 20, we need a zero right here. And then we can multiply. So we'll start with 2 * 4. That gives us 8. Then we have 2 * 5, that's 10, carry the 1. And then we have 2 * 1, which is 2 plus that 1 is 3. So 154 * 20 = 3,080. And now we add 924 and 380. We'll start with 4 + 0, that's 4. Then we have 2 + 8, that's 10. So write our 0, carry the 1. Then we have 1 + 9 is 10 + 0 is 10. So a zero, carry the 1. And then we have 1 + 3 which is 4. So we end up with 44. And that's our final answer. We are done. Let's move on to number two where we have 795 * 83. So let's set this up. 795 * 83. So we'll do 795 * 3 and then 795 * 80 and then add those to get our final answer. So we'll start with 3 * 5 here that's 15. Carry the 1. Then we have 3 * 9 which is 27 + 1 is 28. Carry the 2. And then we have 3 * 7 which is 21 + 2 is 23. We are done with this three. Done with this one. And done with this two. Now we move over to the eight in the 10's place. So we need our zero here. And then we can multiply. We start with 8 * 5. That's 40. So write our zero and carry the four. Now we have 8 * 9 which is 72 + 4 is 76. So write our 6, carry the 7 and then next we have 8 * 7 which is 56 + 7 is 63. So 795 * 3 is 2,385 and then 795 * 80 is 63,600. So let's add these for our final answer. 5 + 0 is 5. 8 + 0 is 8. 3 + 6 is 9. 2 + 3 is 5. And then we have a six in the 10,000's place. So our final answer 65,985. So those were our two example problems. Let's move on to some practice problems that you can try on your own. So have paper and a pencil ready. So here are your practice problems. I'll give you three minutes and then we will go over the answers. Feel free to pause the video if you need more time or jump ahead to the answers if you're ready. Go ahead and start. Do you feel Okay, so that was 3 minutes. Let's go over the answers. So, here are our answers for number one. 242 * 39 = 9,438. For number two, 951 * 75 = 71,325. So, there you have it. There's how to multiply a three-digit number by a two-digit number. I hope that helped. Thanks so much for watching. Until next time, peace.