Tag Archives: revision

Primary 3 February Review 3

P3-Feb-Review 3

Ans:

1–  2

2–  4

3–  2

4–  2

1233 + 3870 = 5103

5103 – 1789 = 3314

 

5–  3

heart= 68 ÷ 4 = 17

159 + 17 = 176

 

6–  2

7–  4

8–  1

9–  1

709 – 163 = 546

546 ÷ 7 = 78 bags

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Primary 5 CA1 Revision 11

P5-CA1-Ex11

Ans:

1–  3 000 303

2–  8

3–  49   1/2

4–  2500

5–  4   5/12

6–  18

7–  2   31/48

8–  2   19/24 kg

9–  $104

Cost of 4 pens –>  4 × $12 – $48

$48 + $56 = $104

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Primary 3 January Review 5

P3-Jan-Review 5

Ans:

1–  3

2–  2

3–  2

[Option 1 is the smallest value but it is an odd number]

 

4–  2

The smallest possible even number that can be formed is 3470.

 

5–  1

482 – 253 = 229 blue marbles

253 -229 = 24 more black marbles

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Primary 4 CA1 Revision 4

P4-CA1-Ex 4

Ans:

1–  2

2–  4

3–  4

4–  4

5–  4

6–  2

7–  4

3000 + 78 230 = 81 230 = 75 thousands, 62 hundreds, 30 ones

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Primary 2 January Review 1

P2-Jan-Review 1

Ans:

1–  2

2–  2

2 hundreds = 200

3 tens 6 ones = 36

200 – 36 = 164

 

3–  2

4–  4

5–  2

5 hundreds 2 tens = 520

3 hundreds 1 ten 4 ones = 314

520 – 314 = 206

 

6–  1

7–  1

8–  3

700 – 500 = 200 = 20 tens

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Primary 3 January Review 4

P3-Jan-Review 4

Ans:

1–  3

2–  2

[Add 201 to the previous term]

 

3–  2

4–  3

5–  4

6–  3

7–  3

9000 – 60 = 8940

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Primary 3 January Review 3

P3-Jan-Review 3

Ans:

1–  2

2–  3

3–  3

4–  3

5–  4

6–  1

7–  4

8–  3

9–  4

Number of girls in the class ->  24 + 5 = 29

29 + 24 = 53 pupils

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Primary 3 SA2 Revision 7

P3-SA2-Ex 7

Ans:

1–  2

2–  4

3–  4

4–  1

5–  2

6 + 12 + 18 + 24 = 60

60 ÷ 6 = 10

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Primary 6 August Problem Sums 9

P6-PSP-Aug-Ex 9

Ans:

1– 28 cm

Square numbers are 1, 4, 9, 16, 25, 36, 49, 64, 81, etc …

The two possible square numbers that add to 74 are 25 and 49

5 cm × 5 cm = 25 cm²

7 cm × 7 cm = 49 cm²

7 cm × 4 = 28 cm

 

2–  355 more marbles

Number of boys –>  3 + 5 = 8

Units of marbles each girl received –>  1u

Units of marbles each boy received –>  1u + 30

Total received by the 8 children –>  1u × 3 + (1u + 30) × 5 = 8u + 150

8u + 150 marbles ->  570 marbles

8u –>  570 – 150 = 420 marbles

1u –>  102.5 marbles

(5u + 150) – 3u = 2u + 150

(102.5 × 2) + 150 = 355 more marbles

 

3–  $71.50

7 durians + 10 mangoes –>  $57

[1 durian + 1 mango –>  $7.50] × 7
–>  7 durians + 7 mangoes –>  $52.50

Therefore, $57 – $52.50 = $4.50 –>  3 mangoes

1 mango–>  $4.50/ 3 = $1.50

1 durian –>  $7.50 – $1.50 = $6

4 durians + 3 mangoes –>  $6 × 4+ $1.50 × 3 = $28.50

$100 – $28.50 = $71.50

 

4–  15 : 6 : 10

Red   :  Blue                      Blue   :   Purple
5      :     2                             3      :      5

–>  15    :     6                             6      :    10

Red   :   Blue   :   Purple
15   :    6    :   10

 

5–  56 cm

Height of water level at first –>  5/8 × 64 cm = 40 cm

1600 cm³ ÷ (10 × 10) cm² = 16 cm

16 cm + 40 cm = 56 cm

 

6–  200 cookies

[Constant Difference]

At first:

Joanna –>  250 cookies

Sharon ->  350 cookies

In the end –>        Joanna  :  Sharon
3       :         5

2u –>  100

1u –>  50

8u –>  50 × 8 = 400 cookies left

600 – 400 = 200 cookies

 

7–  $13.50

5 small towels + 6 big towels –>  $34.50

6 small towels + 5 bog towels –>  $34.50 – $4 = $31.50

11 small towels + 11 big towels –>  $34.50 + $31.50 = $66

1 small towel + 1 big towel –> $66/ 11 = $6

5 small towels + 5 big towels –>  $6 × 5 = $30

1 big towel –> $34.50 – $30 = $4.50

$4.50 × 3 = $13.50

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Primary 5 CA2 Revision 1

P5-CA2-Ex 1

Ans:

1–  3

2–  1

3–  2

Area of square –>  8 cm × 10 cm = 80 cm²

Base of triangle –>  14 cm – 8 cm = 6 cm

Area of triangle –>  1/2 × 6 cm × 10 cm = 30 cm

80 cm + 30 cm = 110 cm²

 

4–  3

5–  2

1 hour –> 60 min × 60 = 3600 sec

3600/100 = 36 sets of 100 seconds

36 × 10 = 360 lollipops

 

6–  2

11.00 a.m. to 12 p.m. –>  $2

12 p.m. to 2.30 p.m. –>  2.5 hours ≈ 3 hours –> 3 × $1 = $3

$3 + $2 = $5

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