Surviving math

Da Qiao Primary School, Singapore

St Edward School, Florida

Da Qiao Primary School, Singapore

17 – 3 =

17 – 8 =

17

10 7

17

14 3

17

9 8

Primary 1 Singapore

St Edward School, Florida

Grade 2 USA

Archipelschool De Tweemaster – Kameleon, The Netherlands

Grade 5 The Netherlands

Archipelschool De Tweemaster – Kameleon, The Netherlands

Grade 5 The Netherlands

King Solomon Academy, London

Year 7 England

www.marshallcavendish.com/education/mci

High School Attached to Tsukuba University, Japan

Draw a polygon with no dots inside it. Investigate.

A polygon has 4 dots on the perimeter. Find an expression for its area.

Grade 9 Japan

Students who have mastered the basic skills which include basic one-step and two-step problems are ready to handle at least the least demanding of the secondary courses.

999 – 724 = 275

1000 – 724 = 276

12 ÷ 4 = 3

2 tenths ÷ 4

20 hundredths ÷ 4

20 hundredths ÷ 4 = 5 hundredths

3.05

First Hall

Second Hall

Third Hall9 876 ÷ 3 = 3292

3292 ÷ 4 = 823

823 x 5 = 4000 + 100 + 15 = 4115The second hall (and also the first hall) has 4115 chairs.

First Hall

Second Hall

Third Hall

Handling Information- Metacognition- Adult models the behaviour

Representing Solution- Visualization- Adult coaches “Can you see..?”

Computation- Number Sense- Encourage mental computation

Answer:

43 x 1.2m42 x 1.2m = 42m + 8.4m = 50.4m

50.4m ÷ 36 = 1.4m

1.4

1.4

Handling Information / Correcting Mistake- Metacognition- Adult models the behaviour

Representing Solution- Visualization- Adult coaches – use a diagram- Look for a Pattern- Adult coaches – use questions

Checking Answer- Number Sense- Encourage sense making

Primary 5 student figuring out things on his own.

Number of Girls

11 sweets each

8 sweets each Possible?

3 22+6=28 24+25=49 No

4 33+6=39 32+25=57 No

5 44+6=50 40+25=65 No

6

7

8

9

25 + 2 = 27

27 ÷ 3 = 9

9 + 1 = 10 There were 10 girls.

10 x 8 + 25 = 105 There were 105 sweets.

27 sweets were returned when they decided to have 8 each instead of 11. As each girl returned 3 sweets, there must be 9 girls to return 27 sweets. The last girl took 2 (to make her 6 sweets 8). That is why there were 25 sweets left over.

Men

Women

30

14

13

38

2 units = 385 units = 19 x 5 = 95

14+13=712

512→95

1212→95÷512=19 12=190+38=228

Therewere 228 fruits altogether .

$3

$3 $3

$3 $3 $3

Monday

Tuesday

Wednesday

Thursday

$100

Monday

Tuesday

Wednesday

Thursday

$100 – 6 x $3 = $82

4 units = $821 unit = $82 ÷ 4 = $20.50

$20.50 + $9 = $29.50She saved $29.50 on Thursday.

dots on perimeter dots inside

12 0

8 2

4 4

Sent to me by GOLD 90FMMr Lim packed 387 apples. Each apple had a mass of about 24g.  He put them into three different baskets.   The mass of the apples in Basket A was 3 times that of the apples in Basket C.  The mass of the apples in Basket B is twice that of the apples in Basket C.  The mass of the empty Basket C was 140g.   What was the total mass of Basket C and the apples in it?

A

B

C

387 x 24 g = 9288 g6 units = 9288 g1 unit = 1548 g

The total mass of Basket C and the apples in it is 1548 g + 140 g = 1688 g.

It is about 1.7 kg.

Jane + Xueling50 units

Xueling + Siti64 units

14 units = 14 shells1 unit = 1 shell

Siti collected 30 shells.Xueling collected 34 shells.

257

Jim

George

343 – 257 = 86Together they had 600 stamps

86

Working BackwardsJim’s 7 eighths 343Jim’s 8 eighths 392George had 208

George’s 2 fifths 208George’s 5 fifths 520Jim had 80

Jim’s 1 third 80Jim’s total at first 240George had 360 at first

(a) 41 is under M(b) 101 is under S(c) 2011 is under T …. Really? How do you know?