English for Math

PROPERTIES OF ARITHMETIC OPERATIONS ON INTEGERS

(SIFAT-SIFAT OPERASI HITUNG BILANGAN BULAT)

Sebagai Persyaratan UAS Mata Kuliah English for Mathematic

Dosen Pembimbing :

FERRA DIAN ANDANTY, SS.,MA TEFL

Disusun Oleh :

1.               LENI RAHMAWATI                        (125500190)

2.               ENY WAHYUNING TYAS                         (125500060)

3.               KHUSNUL YAQIN                          (125500177)

Ø BEGINNING THE CLASS

T   : Good Afternoon students

S   : Good Afternoon, Ms.

T   : How are you today ?

S   : I’m fine thanks.

T   : Before studying, let’s pray together.

: Finish.

: Okay, who is absent today ?

S   :

T   : Today, we are going to learn about properties of arithmetic operations on integers. Is there anyone already understood about it ?

                                                        

                                                         Or

T   : Properties of arithmetic operations on integer there are three properties that commutative, associative, and distributive properties. Maybe you ever use these properties, but do not know the name of it is properties.

       Actually what is it ?

     : The first commutative is exchange properties where a number.

       These are applies to properties of addition and multiplication. Look at the picture !

      

       Marbles Andi                          Marbles Budi

     (Andi has 5 red marbles and 3 black. Budi has 3 red marbles and 5 black marbles. Are they same number of marbles owned by Andi and Budi ? ).

S :

T : How many marbles are Andi and Budi owned ?

S : 8 point.

T : Now, Andi marbles put into four plastic bags. Each bag contains 2 grains. Budi marbles put into 2 plastic bags. Each bag contains 4 grains. Andi and Budi marbles can be written as follows :

     Andi marbles : 2 + 2 + 2 + 2 = 4 x 2 = 8

     Budi marbles :                 4 + 4 = 2 x 4 = 8

T : In general, the commutativity of additon and multiplication can be written :

       a + b = b + a and a x b = b x a, with a and b any integer. Do you understand ?

S : Yes

T : Then, the assosiativity or grouping

     : This applies to properties of addition and multiplication. Look at the picture !

      

          Doni marbles                   Sandi marbles

(Doni has 2 boxes of marbles. Box I contains 3 red marbles and 2 black marbles. Box II contains 4 blue marbles. Sandi also have 2 boxes of marbles. Box I contains 3 red marbles.  Box II contains 2 black marbles and 4 blue marbles).

     : So, Doni and Sandi marbles can be written : ( 3 + 2 ) + 4 = 3 + ( 2 + 4 )

     : Of the sample. In general, the associative can be written :

       ( a + b ) + c = a + ( b + c ), the formula also applies to multiplication by replacing the plus sign ( + ) to mark time ( x ). That  ( a x b ) x c = a x ( b x c ). Do you understand ?

S : Yes

T : The last is the distributive of multiplication. Do you know about it ?

S : No…

T : The distributive can be called also by the nature of deployment. The distributive of multiplication, there are two kinds of the distributive of multiplication to addition and subraction. In general, these properties can be written :

     a x ( b + c ) = ( a x b ) + ( a x c )

     a x ( b –  c ) = ( a x b ) – ( a x c )

     : Do you understanding ?

S   : Yes

T   : To make you have clear understanding, make of  two to complete these questions. You have five minutes to do this.

 S  : ( Does questions )

T   : Okay finish, the representative each groups come to the front of class and do the questions.

S   :

T   : Good…Good…Good

     : This means, that the day we get new knowledge about the properties of arithmetic operations on integer. How many properties in there ?

S   : There are 3 properties.

T   : Mention, please….

S   : ( Three people)

T   : All right

Ø ENDING THE CLASS

T   : Okay, enough for today, don’t forget studying at home. Let’s close our lesson by praying together.

     : Finish…

     : See you next week.

Ø QUESTIONS

·    Group 1

Answer The Questions !

1.      25 + 10 + 15 = …..( Use commutative and assosiative ). 

2.      Ria and Siska go to fish market. They buy 4 kg and 5 kg, in each kg there 5 fish. How many are they ? ( Use distributive).

·    Group 2

Answer The Questions !

1.      45 + 36 + 21 = …..( Use commutative and assosiative ).

2.      Desi and Della go to fruit market. They buy apples 2 kg and 1 kg, each kg there are 5 apples. How many are they ? ( Use distributive ).