1. Form 1 Mathematics Chapter 2 and Chapter 4

2.  Correction of Open Book Quiz (Chapter 1) ◦ Today!!!  Correction and Parent Signature of Close Book Quiz (Chapter 1) ◦ 24 Oct (Wed)  Standard Homework (I) – Orange ◦ 24 Oct (Wed)  You must hand in on time!

3.  Result of Close Book Quiz ◦ Full mark: 36 (not 40!) and 10 bonus ◦ Highest: 44 ◦ Lowest: 11 ◦ Average: 24.7 ◦ Number of students below 20: 11  Major Problems ◦ Careless Mistakes! ◦ Wrong calculations! ◦ No English answers

4.  Result of Close Book Quiz  5 th place:LAW Cheuk Hang Ellis WONG Pui Yin, Paul  4 th place:WU SHAN Hao Yi  3 rd place:FU Ling Yin  2 nd place:LI Ming Chun Edward  1 st place:LI Sai Kong Congratulations!!!!!! Well done!!!!!!

5.  Restaurant problem: ◦ 3 students went to a restaurant for a meal of $250. ◦ Everyone firstly paid $100. So, totally $300 ◦ When the waiter came back with $50, they decided to get $30 back (everyone gets $10 back) and then left $20 for tips. ◦ So, every student paid $90 only.  Now, $90 x 3 + $20 = $290!  Where is the last $10?

6.  Money is there!  Only the calculation is wrong!  The money given by the students (-) ◦ $90 x 3 = $270  The money goes to (+) ◦ $250 (to meal) + $20 (to waiter) = $270!  So, the information is correct.  The only problem is we have mixed up the calculation!  If we can understand better Directed Number, we will not have this problem!

7. Ronald HUI  Arithmetic Operations  “+” – Addition ◦ Add… to…PlusSum  “–” – Subtraction ◦ Subtract… from…MinusDifference  “x” – Multiplication ◦ Multiply… by…TimesProduct  “  ” – Division ◦ Divide… by…OverQuotient  “=“ – Equals/ is equal to

8. ( + ) ( + ) = ( + )( – ) ( – ) = ( + ) ( + ) ( – ) = ( – )( – ) ( + ) = ( – ) 正正得正負負得正 正負得負負正得負

9. ( + ) ( + ) = ( + ) ( – ) ( – ) = ( + ) ( + ) ( – ) = ( – ) ( – ) ( + ) = ( – ) (+ A) + (+ B) = A + B (+ A) + (– B) = A – B (– A) + (+ B) = – A + B (– A) + (– B) = – A – B (+ A) – (+ B) = A – B (+ A) – (– B) = A + B (– A) – (+ B) = – A – B (– A) – (– B) = – A + B

10. ( + ) ( + ) = ( + ) ( – ) ( – ) = ( + ) ( + ) ( – ) = ( – ) ( – ) ( + ) = ( – ) (+ A)  (+ B) = A  B (+ A)  (– B) = – (A  B) (– A)  (+ B) = – (A  B) (– A)  (– B) = A  B (+ A)  (+ B) = A  B (+ A)  (– B) = – (A  B) (– A)  (+ B) = – (A  B) (– A)  (– B) = A  B

11. Ronald HUI  Consider A as a variable ( 變數 )  We know 3A = A + A + A or 3A = 3  A  So, can we write: A  7 = A7orA  7 = 7A ?  Which is correct: B  A = BAorB  A = AB ?  How about: 3A  4B?3A4B / 12AB / 12BA / AB12  What if-3A  -4B?

12. Ronald HUI  Pay attention to the followings:  Consider A as a variable ( 變數 )  1  A = A  A + A + A = 3A  A  A  A = A 3  3A  4A = 12A 2

13. Ronald HUI  When we work on the followings, we should put together the like terms and then simplify!  For examples: 1.A +2B +3A +4B= A +3A +2B +4B = 4A + 6B 2.A -2B –3A +4B= A -3A -2B +4B = (A-3A) + (-2B+4B) = (-2A) + (2B) = -2A +2B

14.  Page 77 of Textbook 1A ◦ Class Practice

15. Ronald HUI  Addition of equality ( 等量相加 ) X – 7 = 2 X -7 +7 = 2 +7 X = 9 X – 7 = 2 X = 2 +7 X = 9

16. Ronald HUI  Subtraction of equality ( 等量相減 ) X + 7 = 12 X +7 - 7 = 12 -7 X = 5 X + 7 = 12 X = 12 -7 X = 5

17. Ronald HUI  Multiplication of equality ( 等量相乘 ) X  5 = 4 X  5  5 = 4  5 X = 20 X  5 = 4 X = 4  5 X = 20

18. Ronald HUI  Division of equality ( 等量相除 ) 5X = 20 5X  5 = 20  5 X = 4 5X = 20 X = 20  5 X = 4

19.  Page 91 of Textbook 1A ◦ Class Practice

20. Ronald HUI  Use a letter x to represent unknown number 設 x 為變數 ( 即想求的答案 )  Follow the question and form an equation 根據問題，製造算式  Solve for x 算出 x 的值  Write answer in words (with units!) 寫出答案 ( 包括單位 )

21. Ronald HUI  If the sum of 3 consecutive ( 連續 ) numbers are 69, find these numbers.  Let x be the smallest number. Then, x+1 and x+2 are the next 2 numbers  Then,x + (x+1) + (x+2) = 69 x + x +1 + x + 2 = 69 x + x + x + 1 + 2 = 69 3x = 66 => x = 22.  So, the numbers are 22, 23 and 24.

22.  Page 99 of Textbook 1A ◦ Questions 3 – 9

23.  Correction of Open Book Quiz (Chapter 1) ◦ Today!!!  Correction and Parent Signature of Close Book Quiz (Chapter 1) ◦ 24 Oct (Wed)  Standard Homework (I) – Orange ◦ 24 Oct (Wed)  You must hand in on time!

24. Good Luck! Enjoy the world of Mathematics! Ronald HUI