Monday, 20 January 2014

Review: Homework Chap 1 Q4

Workbook (p2) Q4: Find the prime factorisation of each of the following numbers, leaving your answer in index notation

Examine the following working:
(1) Has the student answered to the question? If not, what's wrong in the way the answer is presented?
(2) Is the overall working clearly presented to demonstrate the student knows what he/she needs to find? If not, how could the working/ presentation be improved?

* Afternote was added to the end of each case, after discussion with the class on 20 January.

Case 1:

Afternote:
The student had done the Prime Factorisation correctly. 
The question asked for prime factorisation and answers be presented in Index Notation.
However, the student did not answer to the question. Instead, he/ she listed all the factors of the number, which is not required.

Case 2:

Afternote:
The student had done the Prime Factorisation correctly. 
However, he/ she did not understand what is meant by 'index notation' (see the arrow he/ she drew, pointing at "1").
In addition, though he/ she had written "2^3 x 7 x 11 x 13", his/ her final answer was 8008.

Case 3:

Afternote:
The student had done the Prime Factorisation correctly. 
3^2 (5 x 7) is a mixed presentation of "multiplication". He/ She should have written it as 3^2 x 5 x 7. 
In addition, from the presentation, he/ she had 315 as the final answer. So, it is an indication of not understanding what "index notation" means.

Case 4:

Afternote:
The student had done the Prime Factorisation correctly. 
(2^3 x 7) x (11 x 13) is a mixed presentation of "multiplication" and the "operation"/ working seemed incomplete. He/ She should have written it as 2^3 x 7 x 11 x 13

Case 5:

Afternote:
The student had done the Prime Factorisation correctly; however, he/ she had not carried it out in a systematic manner. 
As a good practice, we should always test the division with the smallest possible prime number (divisor) before moving on to the next one so that we need not to do further "random checks" in subsequent divisions - for the ease of checking and accounting for all possible prime factors involved.

Similarly, when writing the product of prime factors in index notation, It would also be a good practice to start with the smallest prime factor (in ascending order) - for the ease of checking.

Discuss it as a group and comment for all the cases

Remember to sign off with your Group number.

24 comments:

  1. This comment has been removed by the author.

    ReplyDelete
  2. This comment has been removed by the author.

    ReplyDelete
  3. This comment has been removed by the author.

    ReplyDelete
  4. Group 1
    Case 2
    The student has answered the question and there is nothing wrong with the presentation

    ReplyDelete
  5. Group 1, Elgin Ng
    Case 4:
    1. He/she does not have to put brackets.
    2. The overall working clearly presented to demonstrate the student knows what he/she needs to find

    ReplyDelete
  6. Group 3: Khoo BOsi
    case3
    doesnt need a bracket

    ReplyDelete
  7. the student did not list the factors not the multiples gp4 case 1

    ReplyDelete
  8. Group 1: owen
    Case 3
    1. the person does not need to put the brackets for 5]the numbers 5 and 7.
    2.When done, the person should put ANS or double stroke his or her answer.

    ReplyDelete
  9. Group 2: Javier Liew
    Case 4
    U dont have to bracket the answer

    ReplyDelete
  10. GRP2, Wong Kang
    CASE3: The 3^2(5X7) Should be written as 3^2X5X7 and that would be the ans instead of 315

    ReplyDelete
  11. Grp 1 Joshua Chua
    Case 5
    The first three prime numbers should be 2 followed by 7,11,13
    but the answer is still correct

    ReplyDelete
  12. Group 3: Low Tjun Lym
    Case 2
    The arrow pointing to the '1' is not correct as index notation is not represented there. The arrow should point to the answer as it is left in index notation.

    ReplyDelete
  13. Group 2, Celest Oon
    Case 2:
    1. The number 1 is not the index notation.
    2. He did not label his answer.

    ReplyDelete
  14. group 2
    joshua yew
    case 1 the answer has to be written like this : 2^3X7X11X13

    ReplyDelete
  15. Group 4,Dominic Hong
    Case 3: Forgot to write the multiplication sign at the bracket and the bracket isn't necessary.
    Never put like 3x3x5x7

    ReplyDelete
  16. Group 4: Woon Yoke Xuan
    Case 4:
    There isn't a need for the bracket to "group" the numbers.

    ReplyDelete
  17. Group 3: Christopher Yong
    Case 5
    It is not systematic and you should always start with the smallest number possible.

    ReplyDelete
  18. Group 2: Fyodor Lee
    Case 2
    The working and the presentation was both fine.

    ReplyDelete
  19. Group 6
    Moon Gijoo
    Case 5

    Yes.
    No. During the prime factorisation, lowest prime number should the one to be divided first.

    ReplyDelete
  20. Group 5 Joel Tio
    Case 3
    Missing line below 1.
    Missing Ans.
    Missing multiplication sign.

    ReplyDelete
  21. Group 5 Joel Tio
    Case 5
    Non-systemactic
    Missing Ans.

    ReplyDelete
  22. group 5
    case 2
    javier yeo
    The student did not draw a line between the 8008 and 4004 of the chart.
    The 8008 is supposed to go before the number sentence.
    The index notation is not the number 1

    ReplyDelete
  23. Group 5
    Case 4
    The numbers don't have to be bracketed as there is only multiplication in the whole equation

    ReplyDelete