## Wednesday, 7 January 2015

### Key Takeaways from Lessons 1 & 2 (8, 9 Jan)

Post as comments below, four learning points, from the lessons.

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3. i have learnt to prove if a number is prime number today

4. I learn about how to check if the number is prime number or composite number and the difference between them. I also learn the characteristic of a prime number (If its divisible by itself or 1).

5. 1. square root the number
2. look for all prime numbers less than the answer in (1)
3. divide the number by the numbers in (2)
4. if the number is divisible by any of the numbers, it is not a prime and vice versa

1. this is how to find out whether a big number is a prime

6. I have learnt what the prime numbers below 100 are and learnt about the Sieve Of Eratosthenes. I have also learnt more about the definition of prime and composite numbers and realised that 1 and 0 are neither prime nor composite.

7. 1. 2 is the only even number which is a prime number
2. The product of 2 prime numbers is equal is always composite
3. Every prime number is an odd number except 2
4. Every odd number is a prime number

8. I learnt the trial division method, i have learnt the 2 factors of a prime number
i have learnt that a prime number must be a whole number

9. 1. 2 is the only prime number
2. prime numbers are larger than 1
3. I also learnt how to find out if a number is a prime number.
4. a prime number has 2 factors only

1. i'm quite sure the number "2" is not the only prime number

2. (1. 2 is the only prime number that is even)sorry bout that

10. Key Takeaways from lessons 1 & 2 [ 8 & 9 January 2015 ]
I have learnt .....
1.The number "2" is the only even prime number.
2. Prime numbers can only be divided by "1" and itself, in other words having only 2 factors.
3. I learnt that the sieve of eratosthenes can assist in finding prime numbers under 100.
4. I've also learnt that composite numbers have more than 2 factors and prime numbers only have 2 factors.

11. I have learnt:
1. Trial division
2. Testing the primality for a number
3. 2 is the only even number that is prime
4. Natural numbers start from 1 whereas Integers consist of negative numbers, positive numbers and 0.

12. 1) I learn about concluding prime numbers
2) prime numbers is not all odd numbers
3) the way of finding a large prime number we have to divide by the prime numbers smaller then its square root
4) The product of two prime numbers is always a composite

13. 4 Key Learning Points:
- Prime numbers have 2 factors.
- All even numbers except 2 are not prime.
- Not all even numbers are prime.
- The product of 2 prime numbers would always be a composite number.

14. I have learnt....
~ Prime numbers have two factors
~ The trial division method
~ two prime number add up together will become a composite number.

15. I have learnt.....
- Prime numbers have 2 factors, 1 and itself
-The sum of two prime numbers, no matter if they are the same, will give a composite number
-"2" is the only prime number that is even

16. I have learnt...
- a shorter way to find if a number is prime
- the definition of a prime number is : the only factors is 1 and itself
- the sum of two prime numbers will be a composite number
- "2" is the only even prime number

17. 4 Key learning points
-Prime numbers have exactly 2 factors.
-All prime numbers, except for 2, are odd numbers
-The sum of two prime numbers is always a composite number
-Not all odd numbers are prime.

18. 4 Key learning points I've learnt
- All Prime numbers have to be over the number 1
- Prime numbers should only be divisible by 1 and itself
- All even numbers other than 2 are composite
- The number 1 is not a prime number as people often think

19. 4 Learning points:

I have learn the difference between natural numbers and whole numbers.
I know how to sieve out primes numbers.
2 is the only even prime number.
I know what is a prime number and a composite numbers.

20. 1) I learnt that 1 is neither composite nor prime.
2) I learnt that natural numbers and whole numbers are different.
3) I learnt to sieve out prime numbers from 1-100.
4) I know how the methods to find out whether a number is prime

21. 4 key learning points
~ To know if no. is a prime, divide by 2, 3, 5, 7, 11 or 13
~ Not all odd numbers are primes
~ Prime numbers are not divisible by any number except for itself
~ All even numbers larger than 2 is not a prime number
Done by: Berniss Chow Zi Min using Yi Zhen's computer