Hello everybody
Today we're gonna talk about math
In my channel I speak about curiosities, mathematical curiosities
Basic mathematics, high school mathematics, calculous
Everything about mathematics
Parodies!
You will learn mathematics and you will have a entertainment time
YEEEAAAH!!!!! I love it!
Entertaining time
Good good!
So, I noticed that besides loving math, you also love languages, right?
Yes, I know English and I know Spanish as well
And how did you learn these languages?
By myself! Playing video games, listening to music, watching movies with English subtitles. It helps a lot.
And how did you improve your speaking?
By hosting people from all around the world
- I hosted people in my house - Really?
- In Rio, right? So you have a lot of tourists there - Yes
I hosted about 200 people in my house
- Come on, 200 hundred?! - Yeah, 200 hundred!
Do you remember this number?
Good!
- Gooood! Excellent!! - Oh yeah, I'm good
You good!
Excellent, come on!
Exactly, very good!
So let's talk about the math operations now Rafa
What are the four basic math operations?
We have: addition, subtraction, multiplication and division
- These are the four basic ones, but we have other ones - Okay
We have, for example, percentage.
We have fractions
We have exponentials
- We have logarithms - Okay
- We have square roots - Square root
So, let's talk about addition
Addition because we add something
When you go to Facebook for example and you add someone
Sometimes you say "I add"
Add on Facebook
Two add two
For example
Is equal to 6 or is 6
Exactly!
Some, some people. There are some people here
So, what's the sum of two and two?
- Four - Four, exactly
- So let's talk about subtractions - Subtractions
How much is...
Minus, minus two... Minus, minus is plus
So... It's six!
So now let's talk about the third math operation which is division
Division! Let´s go
And how do you say "dividido por dois"
Divided by...
Or, if it is a fraction, we can say two over two
It´s the same thing as one
Multiplication!
Two times two is equal to four
And do you have any tip for us to memorize the times table?
Because some people can may find it kind of hard
- The most viewed video of my channel, is the one that I teach how to memorize a times table - Oh good!
Actually, you don't have to memorize the times table
Because you already know it
Do I ?
Because you just have to know the times table of one, two, five and ten
Tell me more about it
- For example, if you have seven times eight, which almost nobody knows. How much is it? - Yeah, I have to think a lot
So you can transform the seven in five plus two
Five plus two is seven
And then you apply the distributive property
- Five times eight and two times eight - Okay
Five times eight? Fourty!
- Two times eight? Sixteen - Sixteen
- So it´s sixty... Okay - Now you add
- Fourty plus sixteen, fifty six - Fifty six
Very easy
It´s a nice trick
You just have to know the times table of one, two, five and ten
Nineteen times eight... Well I can transform the nineteen on a twenty minus one
Alright
And now distributive property
Twenty times eight is one hundred and sixty
One times eight is eight. So now you subtract
One hundred fifty two
Subtraction now
Two hundred and fifty minus thirty four...
It is two hundred and sixteen
Excellent!
And now addition, okay? The last one
One thousand and twenty five plus three hundred and fifty
So it is one thousand three hundred and seventy five
Exactly, good!
- I guess he's good - Thank you very much!
Oh yeah, two challenges
The first one is the easy one
- Pause the video you... pause the video, try to do it - Pause the video
Now the second one is an arithmetic challenge for you
So nine minus three divided by one third plus one. How much is it?
I have no idea
So thank you very much Rafa for helping me with this video
Thank you very much for inviting me to make this video with you
I'm really happy, and I'm surprised because your English is great! Congratulations
Thank you very much teacher. Your mathematics is great as well
Just for the easy one, because the other one I have to think a lot, I don't know
- Just the basics -Yeah, just the basics
So, I hope you like this video
If you like this video subscribe to "English in Brazil" and to "Mathematics River"
WE'RE TOGETHER!
We're together, yeah!
Bye bye, see you!