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

Common percentages


2m read
·Nov 10, 2024

  • [Instructor] What I would like you to do is pause this video and see if you can calculate each of these percentages, and ideally do it in your head.

All right, now let's do it together. Now I said, how are you going to do it in your head? You might be tempted to write down these as multiplication problems and have to write it down. And that might be a reasonable thing, but these are particular percentages that you might see a lot of in life, and so it's useful to think about them in your head.

For example, 1%. 1% is the same thing as 1 over 100. So 1% of 900 is the same thing as 1/100 of 900. And so this question boils down to really what is 900 divided by 100. And that, of course, is equal to 9.

Let's do another example. What's 10% of 630? Well, 10% is equal to 10 over 100, which is the same thing as 1 over 10. So if I were to say 10% of 630, that's the same thing as saying 1/10 of 630. So this all boils down to 630 divided by 10, which you would recognize as 63.

All right, let's do this next one, 20% of 45. You might recognize already, and if you haven't already, it's good to recognize that 20% is the same thing as 20 over 100, or that it's the same thing as 1 over 5. It's good to just know that, hey, 20% is 1/5. So if I'm saying 1/5 of 45, that's the same thing as 45 divided by 5, which is, of course, equal to 9.

Let's keep going. This is too much fun. 25%, you might recognize that's the same thing as 1/4. 25% is 25 over 100. If you divide the numerator and the denominator by 25, you're going to get 1 over 4. So this is equivalent to saying what's 1/4 of 28. Well, 28 divided by 4 is, of course, 7.

Let's keep going. 50% of 128. You might recognize 50% is the same thing as 1/2. It's 50 over 100, which is equal to 1/2. And so we're really just saying what's half of 128, or what's 128 divided by 2. And that, of course, would be 64.

And then last but not least, 400% of 8. Well, 400%, that's the same thing as 400 over 100, or it's equal to 4. So that's really saying what's 4 times 8. So 4 times 8 is, of course, equal to 32.

And we are done.

More Articles

View All
Kevin Hale - How to Improve Conversion Rates
So this presentation on improving conversion rates is designed to mostly focus on landing pages. But all of the principles and ideas that I’ll talk about in this talk actually can help you improve the conversion rates of almost anything, any user interfac…
How has the position of Speaker changed over time? | US Government and Civics | Khan Academy
How is the position of Speaker of the House changed over time? The position of Speaker of the House has changed a lot over time, and it has had powerful early advocates. Henry Clay, an early Speaker of the House who had three different terms as Speaker, …
TIL: Wild Lions Live in India | Today I Learned
[Music] Most people think about lions in Africa, but very few people know that they actually exist in India too. It looks, uh, not very different from the African lion. It is, however, a bit smaller. It does have flappy skin on the stomach that looks diff…
Death & Dynasties
Rulers are often related, with power passing from member to member, forming a dynasty. This occurs not just with royalty or dictators, but also with representatives in a democracy. Families frequently pass power or compete with other families for a turn a…
How My School Teachers Influenced Me - Smarter Every Day 284
Hey, it’s me, Destin. Welcome back to Smart Every Day. I had an opportunity to do an event locally where I got to make a video to thank some of my teachers, and it was awesome. And when I got done making this video, it’s super sweet. Some of my teachers …
Are we in a REAL ESTATE BUBBLE?!
What’s up you guys? It’s Graham here. So first off, I want to say this is a bit of a technical video. It might be a little bit more in-depth than the other videos I’ve done, but for those that are into that sort of stuff, I think you guys are really going…