- Видео 155
- Просмотров 17 159
On Point Math
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Добавлен 20 янв 2023
How to tell if a number is composite or prime? (1233)
The process of determining if a number is prime.
Просмотров: 48
Видео
Math and politics Episode 2: The plurality method
Просмотров 95 месяцев назад
Here we define the plurality method and look at which of the five fairness criteria it can violate.
How to tell if a number is composite or prime? (149)
Просмотров 885 месяцев назад
The process of determining if a number is prime.
How to tell if a number is composite or prime? (131)
Просмотров 215 месяцев назад
The process of determining if a number is prime.
How to tell if a number is composite or prime? (23)
Просмотров 985 месяцев назад
We look at the process of determining if a number is prime.
How to write 19 as the product of primes; how to find the prime factorization
Просмотров 135 месяцев назад
What is the product of primes and how do you find it?
How to write 1242 as the product of primes; how to find the prime factorization
Просмотров 325 месяцев назад
What is the product of primes and how do you find it?
How to write 35 as the product of primes; how to find the prime factorization
Просмотров 75 месяцев назад
What is the product of primes and how do you find it?
How to write 120 as the product of primes; how to find the prime factorization
Просмотров 365 месяцев назад
What is the product of primes and how do you find it?
Math and Politics Episode 1: The basics of fairness in voting
Просмотров 196 месяцев назад
Join me for a series on the math of politics! We will begin by looking at the basics of fairness and the 5 criteria for fairness in a voting system. In the rest of the series, we will look at 5 different voting systems and how they do (and do not) meet the criteria of fairness.
How to find the length of the diagonal of a square given the side.
Просмотров 1136 месяцев назад
Here we look at the relationship between the side length and the diagonal length of a square.
Why can't you distribute into a square root?
Просмотров 176 месяцев назад
Here we look at a common algebra mistake and why it doesn't work.
How to do integration using u substitution when you have a square root
Просмотров 196 месяцев назад
Here we look at another example of u substitution. The video of why we can't distribute into a square root can be found here: ruclips.net/video/tlEOUbti4ls/видео.html
How to to u substitution for integration
Просмотров 156 месяцев назад
Here we look at an intro level example for u-sub. For another example check out: ruclips.net/video/9qmRIZrGqT0/видео.html
How to find the median
Просмотров 416 месяцев назад
Here we look at a simple data set and how to find the median.
How to find the total surface area of a pyramid
Просмотров 1026 месяцев назад
How to find the total surface area of a pyramid
How to find the lateral surface area of a pyramid
Просмотров 4746 месяцев назад
How to find the lateral surface area of a pyramid
How to find the total surface area of a prism
Просмотров 486 месяцев назад
How to find the total surface area of a prism
How to find the lateral surface area of a prism
Просмотров 676 месяцев назад
How to find the lateral surface area of a prism
How to find the total surface area of a cone
Просмотров 1646 месяцев назад
How to find the total surface area of a cone
How to find the lateral surface area of a cone
Просмотров 3206 месяцев назад
How to find the lateral surface area of a cone
How to find the surface area of a sphere
Просмотров 1026 месяцев назад
How to find the surface area of a sphere
How to find the total surface area of a cylinder
Просмотров 1106 месяцев назад
How to find the total surface area of a cylinder
How to find the lateral surface area of a cylinder
Просмотров 1516 месяцев назад
How to find the lateral surface area of a cylinder
I mean prime numbers in index from
yes it does work with 1
the question is why is half of them in p T or is that just the formula. I'm lost
Hi- are you talking about the first column for p? The first 3 columns of the table have p q and r. We have to generate all possible combinations of T/F for these 3 statements. So in a way yes it is a formula. By making half of the values of p true and half false it helps us set up the table to cover every possible outcomes. Does that answer your question?
@@JessaOnPointMath ooooh yes.... thanks for this. I appreciate 🙏
the question is why is half of them in p T or is that just the formula. I'm lost
thank you
Are you okay? (This is genuine, bc im rlly concerned that you haven't posted in a while yet.)
Hi! Yes I am doing well. I’m on summer break taking some time off before we hit the ground running in the fall! ❤️
What if the length and the perimeter is given but the width is not given but you should find the area?
Hi- the perimeter is 2 widths plus 2 lengths. So if you have perimeter and length, first subtract 2 lengths from perimeter. P - L - L. Then the result is 2 widths. So divide the result by 2 and that will be the width. Then area is length times width. Hope that helps!
Good afternoon ma
Very nice video ❤️
Thank you 🤗
Thank you so much for your channel is so simple and very direct not adding gibberish. 🙏😊😊
I’m so glad you like it!
*_3rd_* comment -- prime (i think)
Hi! 1233 is not actually a prime. It is divisible by 3. ☺️
I pronounce "composite" completely differently to you. Who's right..?
lol good question! I read a lot and have found that I sometimes mispronounce words because I have never heard any one say them! In this instance I am fairly confident that I am using standard American pronunciation. 😁
Nice approach. A question and a thought. It would be great if you could explain why testing up to the square root of the number matters. I'm guessing that if a number is composite, it has two or more divisors, and it can't have divisors that are both larger than its square root. Thus any composite number has at least one prime factor lower than its own square root. Am I right? If so, sharing things like that will make better videos. Second, there are two quick checks that you can do faster than taking a square root. One is that there are tricks for knowing that a number is a multiple of certain primes: 2 - Is the number even? (as you said) 3 - Do the digits add up to three? If and only if so, the number is divisible by three 5 - The number ends in zero or 5. The other trick is to take the possible prime, X, and add one, and also subtract one. If neither X + 1 nor X - 1 is divisible by 6, then the number (for all numbers greater than three) is not prime. I would do these quick checks before calculating the square root for a thorough test.
Hi! Yes it is true that there are more details that can be included in the video. I teach math full time and sometimes it is hard to find a balance between providing enough information to solve the problem and including details like you mentioned in this comment. In general, I think the extra tricks you mention are critical for students prepping for a timed standardized test (the GMAT is notorious for being long and students really need time saving tricks) but for a student in a standard classroom this is less critical. In answer to your comment about why the method works: Yes you have it right. All composite numbers can be written as a product of prime numbers (this is called the prime factorization) and any factors larger than the square root will have a corresponding factor smaller than the square root. (For example 51= 3 times 17. 17 is larger than the square root of 51 but the corresponding factor, 3, is smaller). Thanks for watching!
Nice video, just a thing to speed up the process. to quickly find out if a number is divisible by 3, simply add up the digits, so for 149 thats 1+4+9, if the resulting number is divisible by 3, then the initial number is also divisible by 3, so you can see that 1+4+9=14 and 14 is not divisible by 3, but 159 is, because 1+5+9=15 and 15 is divisible by 3. This step can be in theory repeated infinitely and sooner or later you will arrive at 3, 6 or 9, which are the only three 1-digit numbers divisible by 3.
Hi! Yes this is true and there are a few other tricks for other primes as well. I don’t worry about speed too much in my courses - I prefer a consistent method that works every time even if it is slower. but for students taking a timed standardized test the faster tests are great!
Nice
This helped a lot thanks
I’m glad it helped!!
I loved this - looking forward to the next episode ❤
thank 🫰🫰
Glad it helped!
you mean average....
It is true that average and mean almost always mean (lol) the same thing. But since most textbooks and statistics courses use the term mean, that is what I use for this channel. ☺️
👍thank you 🙏
You are welcome!
❤❤❤❤❤🎉🎉🎉
Great 👍🙏 thanks
Glad it was helpful! Any other questions I can answer?
🙏thanks
You’re welcome!
🙏 thank you
Glad it was helpful!
Very nice 🙏 thanks
Glad it helped!
Well explained 🙏 thank you 👍
My pleasure!
Great job explaining this topic so clearly! 👏🏼
14
Great advice- have you had some experience with this?
Great question! The alternative is to not tell your parents at all… 😉
@@JessaOnPointMathlol
That helped a lot and to the point as well, i thank you for this explanation 😊
I’m glad it was helpful! Let me know in the comments if there are any other questions you need help with. 🙂
@@JessaOnPointMath I need help on time management for productive studies 😅
Don't use a coin scale. Use a magnet or a coin pinger. Or don't accept coins unless you know other ways.
Thanks
You are welcome! Do you have a specific question I can help with?
I’m pretty sure a quadratic is a muscle in the leg. Am I close?
😂🤣 love this!
The answer is yes! I paused the video and added all the numbers up to total 36 which is divisible by 9. Haha!!
Awesome!!
Cool!
Thanks for posting this! Math was my favorite subject in school, but I've forgotten how to solve ... most problems. This is starting to connect the dots again. :)
I’m glad your are enjoying it! stay tuned for more.😁
Wait how could you even get nine with any number 1-10 with or without the optional choice there is no division or anything did you leave out a step?
The final step is to add up the digits which is how you end up with a smaller number. 👍
Nvm got 88 with 2
Start with 2. triple it gives 6. Add 6 gives 12. Triple again gives 36. Double it gives 72. Then add the digits: 7+2=9. 😁
@@JessaOnPointMath ohhhh I thought it was add the digits to the previous number
Oh I see! You can have some fun with it too- it actually works for ANY whole number but you might need a calculator for larger numbers. 🙂
I got 69
Bummer! It is so much fun when it works-what was your starting number?
Woah! Cool😎
bro just made me do math in summer break 😭
🎉 Victory! 😜
👍👍👍ok cantik
Dos not work with 1
It worked when I tried with 1! 😀
Think of a fruit. Any fruit. Now add a celery. Now cut the celery in half. Now take away half the celery and the fruit you thought of. You have half a celery. 💥
Wait a minute! HOW?!?! Now I’m literally gna sit here and do it with every number lol
I love this! It actually works with ANY number… you can try with larger numbers too!
@@JessaOnPointMath lol I did!!! I sat there and did it over and over….I was SHOOKETH! Lol neat trick!!
Awesome!
Fill the 5 L container, put the 3L container in, making 2L, put that in the 3L, repeat and then add the 2L together.
Hi Nathan! I think you are super close- are you getting 2L twice and then dumping them together? Where are you storing the first 2L batch while you measure out the second 2L? Remember you don’t have a 3rd container. ☺️
Fun! Thank you for this trick!! I’m excited to show off my math skills to the neighbor kids 😊
Thank you! The visualization really helps to understand what is happening!!