Minggu, 15 April 2012

Nanda Putri Amalia
11313244012
International Mathematics Education 2011

Lesson: Introduction to Division

Hello and welcome to this video, introduction to division.
What we will do is take a look for some division problems and give you an explanation of the concept.
Here we have a problem,
18 : 2 = 9
18 is called the dividend, this number is being divided into.
2 is called the diviser, this is a number that exactly divide into the divident
9 is called quotient, this a result.

Lets take a look two more word that have to do with division,
1. Divisible. It means can be divided into.
We can say that 18 is divisible by 2 or 9.
2. Factor. Factor is when one number divide exactly into another number.
We can say 2 and 9 is the factor of 18

Example 1
15 : 3 =
15 as a divident
3 as a diviser
and we have to find the quotient
how many times the divise going to divident?
how many times this three going to 15?
we know 3 goes to 15, is five times, so the result is 5

Remember that divisions is the opposite operation of the multiplication operation.
So, when you learning on times tables, its also helping you to learn the division.

4 x 8 = 32
so, 32 : 8 = 4
32 : 4 = 8
It all works together.

Algebra and Its Application part 1 (Basic)

Nanda Putri Amalia
11313244012
International Mathematics Education 2011

From Marsigit's book (MATHEMATICS for Junior High School)
Chapter 1
Algebra and Its Application

Do you still remember the meaning of algebraic expression? Let see the following illustration.
Suppose Nanda is going to buy 5 books and 4pencils. If one book and one pencil are priced x rupiah and y rupiah, how much money that have to bring by Nanda?
Nanda have to bring 5x - 4y rupiahs.
The form of 5x + 4y from the above illustration is an algebraic expression in which:
5x and 4y are called terms,
x and y are variables
5 is the coefficient of 5x
4 is the coefficient of 4y
We can conclude that Algebraic expression is a statement consisting meaningful of coefficients and variables.

The Operations of Algebraic Expression.

Addition and Subtraction
In algebraic expression, we can only add and subtract the similar terms or like terms. The like terms contain the same variable with the same exponent.
There are two steps to add or subtract the algebraic expression.
1. group the like terms.
2. operate each group by adding or subtracting.

Multiplication Operation
1. Multiplication of one term and two terms of algebraic expressions.
this operations follow the distributive characteristic.
a(x+y)=ax+ay or (x+y)a=ax+ay
a(x -y)=ax-ay or (x-y)a=ax-ay
2. Multiplications of two terms and two terms algebraic expressions.
these multiplication can also be done using the distributive characteristics or using multiplication scheme.
(x+y)(a+b)= x(a+b)+y(a+b) = xa+xb+ya+yb

Exponential Operation
1. Understanding the Exponential
Exponential is a recur multiplication of a number. You can expand p^n as follow.
p^n= p.p.p.p.p} n term
example:
2^2 = 2.2 = 4
(3^2)^3 = 3^2 . 3^2 . 3^2 = 3.3 . 3.3 . 3.3 = 3^6

Divisions
1. Divisions of Algebraic expresions containing one terms
In the division of algebraic expressions is known two key terms:




  • divisions with similar terms, such as 4x : x


  • divisions with different terms, such as x^2 : x


Example



(x^3+3x) : x = (x^3 : x) + (3x : x)



= x^2 + 3

Solving Linear Equation part 1

Nanda Putri Amalia
11313244012
International Mathematics Education 2011

An Equation is a statement that two expression on quantities are equal.
An equal sign (=) is always a part of an equation.
Equality can be true, false, or neither.
the example:
3+5=8, this equation is true
8-2=8, this equation is false
now lets take a look an equation that a neither,
x+4=9, so this is neither true or false.
because I don't know what the value of x is?
if x=2, what we get?
2+4=9, so this equation is false
now lets change, if x=5
5+4=9, is true
the goal of this lesson is to find all the values of variable that would make an equation true.


  • a solution is a value that when substituted in place of a variable, makes an equation true

  • the solution set is the set of all solutions, SS = {5}

Example 1


Determine whether x=1 is a solution of the equation 2x+2=4


what should we do?


2( )+2=4


and we want x=1, so I wanna replace the x to 1


2(1)+2=4


we haven't know whether this equation is true or false until we continue until the operations is end


2+2=4


4=4 (reflexive property)


we get the equation is true, so SS={1}