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Mathematics ExercisesMathematics Exercises

SharingSharingKONG Ching-wahKONG Ching-wah

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A caseA case

7x + 4x =11x7x + 4x =11x mx + nx =(m + n)xmx + nx =(m + n)x

7x + 4x =

15x + 23x =

11x + 36x =

38x + 25x =

14x + ax =

ax + bx =

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Assignment is:Assignment is:

- By orderBy order

- No choiceNo choice

- Routine workRoutine work

- BoringBoring

- Too easy/too difficultToo easy/too difficult

- Not align with assessmentNot align with assessment

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12 -35=

-65 - (37) =

23 + (-37) =

-28-(-39) =

-16 - (-37) =

18 - (-7) =

-6 +(-77) =

26 - (-47) =

-36 - (-57) =

-16 +(-37) =

-36 - 57 =

(-36) - (-57) =

-37 -(-18) =

-22 -37 =

-47 -(-18) =

5

-28-(-39) =

5 – 2 = _____

5 – 1 = _____

5 – 0 = _____

5 – (-1) = ____

5 – (-2) = ____

5 – (-3) = ____

5 – (-4) = ____

5 – (-5) = ____

5 – (-6) = ____

5 – (-7) = ____

8 –(-12) = ____

18–(-24) =____

5 – (-7) = _____

4 – (-7) = _____

3 – (-7) = _____

2 – (-7) = _____

1 – (-7) = _____

0 – (-7) = _____

-1 – (-7) = _____

-2 – (-7) = _____

-3 – (-7) = _____

-8 – (-12) = ____

-18–(-24) = ____

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28 -36 35+ -

-+-12 -26 -17 29

++- --22 -33 -1952 13

7

[4

1 －

8

1 ]( )

3

22

-5 [ /16

1

4

7 ]

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4ab + 3a4ab + 3a22b + 2ab b + 2ab Use , and to divide the following expressions into three groups.

xy 3x2y xy2 4xy 2xy2

3x2y -5xy -2x2y 16xy

-23x2y 43x2y -11xy2

7xy -16xy 89xy2

5xy2 -3x2y -34x2y

25xy -19xy2 -20x2y

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2ab + 3a2ab + 3a22bbHow many “7”s are there?2(7) + 3(7) = ___________

How many “x” are there?

2x + 3x = _____________

How many “xy” are there? 2xy + 3xy = ___________

Can we add them up?

2xy + 3x2y = ___________

= ___________

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(4x (4x －－ 3) + (3) + ( －－ 7x 7x ＋＋ 9) =9) =

2x + x =

2x + (-x) =

2x + (-2x) =

2x + (-3x) =

2x + (-5x) =

2 + 5 =

1 + 5 =

0 + 5 =

-1 + 5 =

-2 + 5 =

Group the like terms.

(3x2+5x-8) + (-5x2-7x-6) =

11

120o

OA

B

Find the area of sector OABFind the area of sector OAB

120o = ------- of a circle ?

120o

The area of sector OEF is ?

90o3cm

OE

F

Find the area of the shaded part.

3cm

OE

F

90o

6cm

12

3cm

3cm

3cm3cm

4cm

4cm

12cm

Find the total surface area of the following object.Find the total surface area of the following object.

3cm

3cm

3cm3cm

4cm

4cm

12cm

Total Total AreaArea

No. of No. of piecepiece

AreaAreaDimension Dimension

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Find the total surface area of the following object.Find the total surface area of the following object.

3cm

3cm

3cm3cm

4cm

4cm

12cm

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A Story ModeA Story Mode

I can only do the operations of “multiply

by 2” and “divided by 2” and I can do the

multiplication of all numbers. This is the

way I do 25(47)

Divided by 2 Multiply by 2

25* 47

12 94

6 188

3* 376

1* 752

47 + 356 + 752 = 1175

25(47) = 1175

John

1.1. Find the way that John did his calculation.Find the way that John did his calculation.

2.2. Why it works in this calculation?Why it works in this calculation?

3.3. Is this method applicable to all operation of Is this method applicable to all operation of multiplication of two numbers?multiplication of two numbers?

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When the sum of all the digits in a number is When the sum of all the digits in a number is divisible by 3, this number is divisible by 3. divisible by 3, this number is divisible by 3.

Do you believe? Give your reason.Do you believe? Give your reason.

Believe or not?Believe or not?

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The Design:The Design:

- Of own learningOf own learning

- Of own choiceOf own choice

- Learning taskLearning task

- VarietyVariety

- Suitable challengeSuitable challenge

- Cross topicsCross topics

- Learn new things and strengthen the old.Learn new things and strengthen the old.

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