yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Addition and subtraction with number lines | 2nd grade | Khan Academy


2m read
·Nov 11, 2024

  • [Voiceover] Which number line shows 47 plus 22? Let's see, in this first number line we're starting at 47, then we add 20 to get to 67. And then we add two to get to 69.

So if you add 20, and then you're adding two, you're adding 22. So this one seems right. So let's see why these choices don't seem right.

So this one, we add two to get to 49 and then two more to get to 51. Well this isn't adding 22. This adding two plus two, this is adding four.

To add 22, you have to add 20 and then two. And this choice right over here, we are adding 20 and then we're adding two, but we're not starting at 47, we're starting at 74.

So this is 74 plus 22, so I definitely feel good about that choice right over there.

Let's do a few more examples. Which number line shows 93 minus 76? So let's see, in all of these choices, we're starting at 93.

Here, in this first choice we subtract seven and then six. But it's subtracting 76, you want to subtract 70. And then you want to subtract six, not just seven.

So I don't like this first choice. Here we subtract 60, and then we subtract seven. But that's subtracting 67, not 76. We gotta subtract seven tens.

Seven tens, and then six ones. So here we're subtracting seven tens, we're subtracting 70. And then we are subtracting six ones.

So that's definitely going to be the right choice. So let's see, maybe maybe one more just for fun.

Which number line shows 12 plus 87? So all of these start off at 12, and we're gonna want to add 80 and then add 7. Eight tens and seven ones.

And let's see, this one adds 80 and then we add seven, so yep. Feel good about that one right over there.

More Articles

View All
Witness a humpback whale birth caught on camera in Hawaii | National Geographic
Long before us, great Travelers were crossing our oceans, risking it all to ensure the future of the next generation. This female humpback whale is exhausted; she’s journeyed 3,000 miles to escape the cold, stormy seas of Alaska and find sanctuary here in…
Mary Devotion Around the World | Explorer
[Music] I was approached by National Geographic last year to photograph people’s relationship with Mary. I traveled all around the world to some of the most unexpected places to document this project. I have my own questions about my faith. I was raised C…
No One Can Insult You After This | 6 Best Ways To Get Respect From Others | STOICISM
Every day you walk out the door wearing an invisible armor, bracing yourself against the world’s judgments and expectations. But what if I told you that some of the greatest minds in history, like the Stoics, mastered the art of not just surviving, but th…
Using units to solve problems: Toy factory | Working with units | Algebra I | Khan Academy
We’re told a factory makes toys that are sold for ten dollars a piece. The factory has 40 workers, and they each produce 25 toys a day. The factory is open five days a week. What is the total value of toys the factory produces in a day? Pause this video …
The Aufbau principle | Atomic structure and properties | AP Chemistry | Khan Academy
In other videos, we introduced ourselves to the idea of orbitals, and these are various orbitals in their various subshells that you could find in various shells of an atom. In this video, we’re going to get a little bit more practice with electron config…
#shorts Type-B Dial
So this is a brand known as Loo. There are type A style dials and there are type B style dials. Type B is going to have a different orientation of the hours and minutes. So the hours in this case are on the inside; the minutes are on the outside. That wa…