Student’S WorkSheet - P4MRI IKIP PGRI SEMARANG | …€¦ · · 2012-05-11Student’S WorkSheet ...Direct and Inverse Proportion... ... 8 f) The proportion of empek-empek is equal

...Direct and Inverse Proportion...

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Latticework Evaluation Sheet

No Indicators Question number score

1 To tell example a direct proportion in daily life 1

10 2 To solve the problems a direct proportion in

daily life 40

3 To tell examples an inverse proportion in daily life

2 10

4 To solve the problems an inverse proportion in daily life

40

Student’S WorkSheet



Name of Group : ………………………………………………………………..

Class : ………………………………………………………………..

1. Look at the picture. It is empek-empek, a

traditional food from Palembang. The

price of empek-empek is Rp 1.500,00.

a) If Danur wants to buy 2 empek-empek, how many rupiahs should Danur pays?

How many empek-empek will be got by Danur if he has Rp. 6.000,00?

Complete the following table

The number of Empek-empek Price

1 Rp 1.500,00

2 Rp………..

…. Rp 6.000,00

5 Rp ……….

… Rp 13.500,00

Then, explain how can you get that value?

b) If someone buys more empek-empek, explain what will happen with the

price?

Student’S WorkSheet



c) What is the price proportion of 2 empek-empek to 5 empek-empek? Explain

your answer.

d) What is the price proportion of 9 empek-empek to 5 empek-empek? Explain

your answer.

e) What is the price proportion of 2.000 empek-empek to 3.200 empek-empek?

Give your argument to solve it.

f) What is your opinion about the proportion of empek-empek to the price

proportion? What can you conclude about this case?

g) Suppose the price of 2 empek-empek is Rp 3.000,00, what is the price of 12

empek-empek? Explain your answer.

h) What is the characteristic of a direct proportion?

i) Find the other example of direct proportion in daily life.



2. Look at the picture. It is wingko, a

traditional food from Semarang. Zahra

will hold a party. She has 12 wingko that

will be given equally to each friend she

invites.

a) If Zahra invites two friends, how many wingko will be given to each? If Zahra

invites three friends, how many wingko will be given to each? Complete the

following table

Invited friends Wingko for each

2 …

3 ….

4 …

… 2

… 1

Then explain how can you get that value.

b) If there are more friends to invite, what happens with the wingko for each?

Explain your answer.

c) If the ratio of friends is 2 : 3, what is the ratio of wingko for each? Explain

your answer.



d) If the ratio of friends is 3 : 4, what is the ratio of wingko for each? Explain

your answer.

e) What could you say about the proportion of invited friends and the proportion

of wingko for each? Explain your answer.

f) What is the characteristic of an inverse proportion?

g) Find the other example of an inverse proportion in daily life.



Mom needs 12 eggs to make three cakes. How many eggs are needed for 5 cakes? Explain your answer.

INDIVIDUAL TEST 1



Name : ………………………

Class : ………………………

1. Look at the following Chocolate Cookies Recipe, then answer the following

question.

a. If you want to make three recipes of the chocolate cookies, find the quantity of the ingridients that you need. Explain your answer.

b. Suppose you have only 100 grams of flour, what is the quantity of the other

ingridients that you need to make the chocolate cookies according to the recipe? Explain your answer.

2. The floor of a bedroom has the size of 3 m × 2.4 m. The floor will be covered

with tiles.

Chocolate Cookies Recipe

Ingridients: 100 grams of margarine 150 grams of sugar powder 200 grams of flour 50 grams of chocolate powder 4 eggs

PROBLEM SHEET



a. If the size of each tile is 30 cm by 30 cm, how many tiles will the floor need? Explain your answer.

b. If the size of each tile is 20 cm by 20 cm, how many tiles will the floor need? Explain your answer.

c. The price of a tile with the size of 20 cm by 20 cm is Rp 1.700,00. The price of a tile with the size of 30 cm by 30 cm is Rp 3.600,00. The fee for placing

tiles is Rp 15,000.00 per m2. Complete the following table.

Cost Size

The number of

tile Price Cost Total Cost

20 cm x 20 cm … … … …

30 cm x 30 cm … … … …

Then explain how you can get that result.



A basket of carrots can be finished by 10 rabbits in 6 days. How long the basket of carrots will be empty if 15 rabbits eat the carrots? Explain your answer.

INDIVIDUAL TEST 2



The Answer Sheet and Rubric Assessment of Work Sheet

Solution Score Problem 1 a) Completing table

The number of Empek-empek

Price

1 Rp 1.500,00

2 p

Q Rp 6.000,00

5 r

S Rp 13.500,00

p = Rp 1.500,00 x 2 = Rp 3.000,00 q = ோ .,

ோ ଵ.ହ, = 4

r = Rp 1.500,00 x 5 = Rp 7.500,00 s = ோ ଵଷ.ହ,

ோ ଵ.ହ, = 9

b) If the thing bough increase then the price is also higher c) The price of 2 empek-empek = Rp 3.000,00 The price of 5 empek-empek = Rp 7.500,00 So, the price proportion of 2 empek-empek to 5 empek-

empek = 3.000 : 7.500 = 2 : 5 d) The price of 9 empek-empek = Rp 13.500,00 The price of 5 empek-empek = Rp 7.500,00 So, the price proportion of 9 empek-empek to 5 empek-

empek = 13.500 : 7.500 = 9 : 5 e) The price of 2000 empek-empek = Rp 3.000.000,00

50 3 3 3 3 5 5 5



The price of 3.200 empek-empek = Rp 4.800.000,00 So, the price proportion of 2000 empek-empek to 3.200

empek-empek = 3.000.000 : 4.800.000 = 2000 : 3.200 = 5 : 8 f) The proportion of empek-empek is equal to the proportion

of price. This case is example of direct proportion in daily life.

g) The price of 2 empek-empek = Rp 3.000,00 The price of 1 empek-empek = Rp 1.500,00 So, the price of 12 empek-empek = 12 x Rp 1.500,00 = Rp 18.000,00 h) Characteristic of direct proportion is the proportion of

things that be compared is equal to the proportion of another things.

i) The other example of direct proportion is the amaunt of the gas (litre) and the money should be paid by the buyer. Or other relevan example.

Problem 2 Zahra will hold a birthday party. She has 12 wingko that will be given to each friend she invites equally. a) Completing table

Invited friends Wingko for each

2 p

3 q

4 r

S 2

U 1

p = ଵଶ

ଶ = 6 s = ଵଶ

ଶ = 6

q = ଵଶଷ

= 4 u = ଵଶଵ

= 12

r = ଵଶସ

= 3 b) If invited friends be more then the wingko for each

decrease. c) If the ratio of friend is 2 : 3, then the ratio of wingko is p :

q = 6 : 4 = 3 : 2.

5 5 5 4 4

50 3

3

3 3

3 6 6



d) If the ratio of friend is 3 : 4, then the ratio of wingko is q : r = 4 : 3.

e) The proportion of invited friends is inverse of the proportion of wingko for each.

f) Characteristic of direct proportion is the proportion of things that be compared is inverse to the proportion of another things.

g) Another example of inverse proportion is the number of worker and the number of days needed. Or other example that is releven.

6 6 5 6



The Answer Sheet and Rubric Assessment of Individual Test

Solution Score Test 1 (First Meeting) a) Mom needs 12 eggs to make three cakes. How many eggs

are needed for 5 cakes? An alternative way to answer: First, find out how many eggs needed for one cake. Three cakes need 12 eggs, therefore one cake need ଵଶ

ଷ= 4 eggs.

So, Mom needs 5 x 4 eggs = 20 eggs to make 5 cakes. Test 2 (Second Meeting) A basket of carrots can be finished by 10 rabbits in 6 days. How long the basket of carrots will be empty if 15 rabbits eat the carrots? An alternative way to answer:

Number of rabbits Number of days 10 15

6 P

Based on the proportion, it can be determined the number of days for making the basket of carrots will be empty.

=1015 × 6 = 4.

Hence, if there are 15 rabbits, the basket of carrots will be empty in 4 days.

100

90

10

100

30

60

10



The Answer Sheet and Rubric Assessment of Problem Sheet

Solution Score Problem 1 a) Chocolate Cookies Reciepe a. The quantity of the ingredient of three recipes is

100 x 3 = 300 grams of margarine 150 x 3 = 450 grams of sugar powder 200 x 3 = 600 grams of flour 50 x 3 = 150 grams of chocolate powder 4 x 3 = 12 eggs

b. Suppose we only have 100 grams of flour, it means that we only have a half of ingredient. So, the other ingridients is: 100 : 2 = 50 grams of margarine 150 : 2 = 75 grams of sugar powder 200 : 2 = 100 grams of flour 50 : 2 = 25 grams of chocolate powder 4 : 2 = 2 eggs

Problem 2 a. The size of floor of bedroom is 3 m x 2,4 m

If the size of each tile is 30 cm x 30 cm We can find the number of tiles are needed The area of floor: 3 x 2,4 = 7,2 m2= 72.000 cm2 The area of tile: 30 x 30 = 900 cm2 So, the number of tiles are needed is

௧= ଶ.

ଽ

= 80 tiles. b. The size of floor of bedroom is 3 m x 2,4 m

If the size of each tile is 20 cm x 20 cm We can find the number of tiles are needed The area of floor: 3 x 2,4 = 7,2 m2= 72.000 cm2

50

25

25

50 10

10

Chocolate Cookies Recipe

Ingridients: 100 grams of margarine 150 grams of sugar powder 200 grams of flour 50 grams of chocolate powder 4 eggs



The area of tile: 30 x 30 = 400 cm2 So, the number of tiles are needed is

௧= ଶ.

ସ

= 180 tiles. c. Completing table by calculating this following items.

The price of a tile with the size of 20 cm x 20 cm = Rp 1.700,00 The price of a tile with the size of 30 cm x 30 cm = Rp 3.600,00 The fee for placing tiles = Rp 15.000,00 per m2

We can find the total cost Cost for placing tiles = area of floor x for placing tiles = 7,2 x 15.000 = Rp 108.000,00 Total cost = Cost for placing tiles + total price of tile i) for tile with size 20 cm x 20 cm total price of tile = 180 x Rp 1.700,00 = Rp 306.000,00 So, total cost = Rp 108.000,00 + Rp 306.000,00 = Rp 414.000,00 ii) for tile with size 30 cm x 30 cm total price of tile = 80 x Rp 3.600,00 = Rp 288.000,00 So, total cost = Rp 108.000,00 + Rp 288.000,00 = Rp 396.000,00

30

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Student’S WorkSheet - P4MRI IKIP PGRI SEMARANG | …€¦ · · 2012-05-11Student’S WorkSheet ...Direct and Inverse Proportion... ... 8 f) The proportion of empek-empek is equal