Multiplying 3-digit by 2-digit numbers | Grade 5 (TX TEKS) | Khan Academy

2m read

·Nov 10, 2024

Let's get a little bit of practice multiplying numbers. So, what is 365 times 84? I encourage you to pause this video; hopefully, you have some scratch paper around, and try to calculate what this is.

All right, now let's do this together. What I like to do is, let me first write 365, and then let me write 84 right under that. But make sure that I line up the place values. So I put the eight in the tens place right under that six, and the four in the ones place right under that five.

Now I am ready to multiply. The first thing I'm going to do is I'm going to multiply 365 by 4. So, 4 times 5 is 20; I'll put the zero in the ones place, and I'll regroup that two because it's really 2 tens. So, 4 times 6 is 24 plus that two; we're really talking about 24 tens. So, plus another two tens is going to be 26 tens. I'll put six tens right over here, and then I'll regroup the two up here.

Now I have 4 times 3; it's really 4 times 300. But 4 times 3 is 12 plus those two that I just regrouped is 14. So, let me put the 14 hundreds here. Now, let me worry about this eight. Well, this eight is in the tens place; it's really 80. So, let me just put a zero here.

I start in the tens place, and let me get rid of these characters right over here so I don't confuse myself. So, 8 times 5 is 40; I'll put the zero right over here and regroup the four. 8 times 6 is 48, and then I add that four; it's going to get me to 52. Then, 8 times 3 is 24 plus 5 is going to be 29.

Now I can add everything together: 0 plus 0 is 0; 6 plus 0 is 6; 4 plus 2 is 6; 1 plus 9 is 10; put the zero here and regroup the one. 1 plus 2 is 3, and I'm done. I got 3,660.

Greening of Pittsburgh | Podcast | Overheard at National Geographic

How to communicate with Khanmigo | Introducing Khanmigo | Khanmigo for students | Khan Academy

View All

How One Brilliant Woman Mapped the Secrets of the Ocean Floor | Short Film Showcase

19:12. A German meteorologist named Alfred Wegener proposed the theory about how the Earth’s landmasses formed. He suggested that the great continents of the Earth had once formed a single landmass called Pangaea, which had broken up and drifted apart ove…

Debunking 3 myths about air pollution | Nat Geo Explores

(upbeat music) - [Narrator] Ever think of how many breaths of air you take in a day? It’s a lot, like 20 thousand, give or take a few. All day, all night, our bodies are at work bringing in the good (bell dings) and kicking out the bad (buzzer sounds). Bu…

Climate 101: Deforestation | National Geographic

[Narrator] Forests cover about 30% of the planet. And the ecosystems they create play an essential role in supporting life on earth. But deforestation is clearing earth’s forest on a massive scale. And at the current rate of destruction, the world’s rainf…

Transitioning from Academia to Data Science - Jake Klamka with Kevin Hale

So Kevin, for those of our listeners that don’t know who you are, what’s your deal? I’m a partner here at Y Combinator. I actually was in the second ever batch. I was in Winter 2006 and I founded a company called Wufoo, ran that for five years, and then …

Worked example: alternating series | Series | AP Calculus BC | Khan Academy

What are all positive values of P such that the series converges? So let’s see, we have the sum from n equal 1 to infinity of ((-1)^{n + 1} \frac{p}{6^{n}}). There’s a couple of things that might jump out at you. This ((-1)^{n + 1}) as (n) goes from 1 t…

Origins of the Universe 101 | National Geographic

[Narrator] The universe is everything. From the tiniest particles to the largest galaxies, to the very existence of space, time, and life. But how did it all begin? The origin of the universe is the origin of everything. Multiple scientific theories plus …

Multiplying 3-digit by 2-digit numbers | Grade 5 (TX TEKS) | Khan Academy

More Articles