## Monday, 12 January 2015

### Key takeaways (13 Jan)

Recall 3 key learning points from
- divisibility tests
- prime factorisation
- HCF

1. the prime ladder and factor tree has help me
if the sum of all the digits is divisible by 3 the number is also divisible by 3
it help us see if the number are divisible by 3,5,2,7,11

1. how has "prime ladder" and factor tree helped you?

2. 1.The divisibility test help us find a number prime factors.
2.The HCF is a number that is the largest factor of two numbers.
3.Prime factorisation uses index notation.

1. 2. largest _______ factor of two numbers

3. 1)For the factor tree we can only use prime factors and not anything else
2)max possible of HCF is A
3)the divisibility test is a way to find the prime factorisation of the number using easier ways

1. 2) what do you mean? describe clearly.

4. 1. Even numbers can be divided by 2 and numbers that end with 0 and 5 can be divided by 5
2. You have to use prime numbers to do prime factorisation.
3. The smallest number between the 2 numbers we are comparing is the largest common factor.

1. 3. the largest possible number that can be the HCF between two numbers is the smaller number of the two.

5. 1. Divisibility test is used for checking if a number is prime or composite. The numbers are 2, 3, 5, 7, 11.
2. 0 and 1 are neither prime nor composite numbers
3. HCF is known as the highest common factor which is the highest multiple that the two numbers can be divided by.

1. 3. is it factor or multiple?

6. -if A is smaller than B, the biggest HCF can only be A.
-we can use a factor tree to do prime factorisation
-the index tells you how may times you multiply the base

7. Divisibility test - It is an easier way for us to find the prime factorisation of a number

Prime Factorisation - The helps as find what the prime factors are for a number

HCF - Finding out the HCF can help us with real-life problems in the future

1. 2. prime factorisation helps to express the number as a product of its prime factors.

8. 1. I learnt that we can use the factor tree for prime factorisation.
2. I learnt that the HCF is the largest positive integer that divides the number without a remainder.
3. We can use HCF and LCM concept to solve word problems.

1. 2. it is more precise than that. please try again.

9. 1.useful when there is no calculator
2.uses index notation
3.to summarise the numbers

1. 3. what do you mean "to summarise the numbers"?

10. 1. If the last digit of any number is a even number, it can be divided by 2.(Divisibility Tests)
2. The factor tree can be used to find the prime factors of a prime number.(Prime Factorisation)
3. List out all the factors of both numbers, then summarise the numbers.(HCF)

1. 3. what do you mean "summarise the numbers"?

2. It means to look for the common number with the largest value

11. 1. HCF is the largest factor that is common
2. There are 2 ways to do prime factorization, tree and ladder method
3. How to make a number into index notations

12. 1. The divisibility test if useful if you are not that good in Dividing
2. When working on Prime factorization we must use index notation.
3. Eg, If A is Smaller then B , then the max possible size of HCF is A

1. 2. When expressing a number as prime factors.

13. The Prime ladder and factor tree
The HCF is a number that is the largest of two numbers
Prime factorisation using index notation

14. 1. To find out if a number is prime, just divide it by 2, 3, 5, 7 and 11.
2. Composite numbers can be divided by 1, itself and other number/numbers.
3. Highest Common Factor is the highest common factor shared between two numbers.

15. 1. The highest factor of a number is itself.
2. The HCM cannot be lower than the LCM.
3. HCF stands for Highest Common Factor.

1. There isn't an HCM

16. Divisibility test - is a super easy way to find out the prime factorization of a certain number
Prime factorization - is a process of expressing a composite number as a product of a prime number
HCF - the HCF of two or more non-zero integers is the largest integer that divides the number with no remainder

1. "as a product of prime factors"
"largest integer that is A FACTOR ...."

17. 1. prime factorisation is done by dividing the number by a prime integer which is a factor of the number.

1. 2. how to use a factor treee
3.the divisibility test is great for shorting out prime numbers

18. -A prime number cannot be divided by 2,3,5,7 and 11
-The Factor Tree and Repeated Division
-Divide both numbers by the same common factor, the largest is the HCF and the factor must be lower than the number to divide.

what about the factor tree and repeated division? What to take note of?
the last point must be more concise as well.

19. Divisibility tests
->Divisibility test help me find prime factors.
Prime factorisation
->Use the tree or ladder method to solve prime factorisation.
HCF
->Use the ladder or tree method to find the HCF of numbers.

1. "use the tree or ladder method to PERFORM prime factorisation"

20. 1. You can use factor trees or repeated division to help you in Prime Factorisation.
2. The highest possible common factor is the smaller number.
3. The divisibility test can help you to figure which numbers are prime and which are composite?

21. 1)The repeated division(prime ladder) and the factor tree had helped me to find the prime factorisation of a number.
2)The numbers of the divisibility test are all prime numbers.
3)The highest common factor is the highest number that is common of two or more numbers.

22. 1) Any even number is divisible by 2
2) The HCF of a number cannot be higher than that number itself
3) There are many different ways of figuring out which numbers are prime numbers.