Thursday, September 27, 2012

Subtracting Negative Integers

Introduction to integers:
     Integers are the one of the types of numbers.  Integers are the combination of the positive integer and negative integer with zero.  Positive integers take the form of +1, +2, +3, +4 …etc. Negative integers take the form of -1, -2, -3, -4 ……. Subtracting negative integers we can subtract the both negative integers. In this topic we have to discuss about the rules of Subtracting negative integers with example problems.

Brief Explanation of Subtracting Negative Integers

Important rules:
     We can subtract the one Negative integer from another negative integer. Now the second negative integer can be changed into the terms of positive integer. Because minus into minus we can get the plus. This is one of the rules of multiplication. Now one integer is the negative integer and then the second integer is the positive integer. So we can subtract the large value from the small value and put the larger number sign as the resultant value.
Notation:
Negative integer – negative integer
That is –x - -y
It can be changed to –x + y
Here two cases arise
Case 1: y is the largest value subtract x from y and put the resultant sign as positive.
Case 2: x is the largest value subtract y from x and put the resultant sign as negative.

Example Problems

Example 1:
Subtract -5 from -9
Solution:
Given Subtract -5 from -9
It can be written as
-9 – -5
That is -9-(-5)
Now we can use the multiplication rule negative x negative = positive
Then -9 +5
Now 9 is the largest value subtract 5 from 9 and put the resultant sign as negative.
Subtracting this we can get -4
So the resultant is -4.
Example 2:
Subtract -15 from -7
Solution:
Given Subtract -15 from -7
It can be written as
-7 – -15
That is -7-(-15)
Now we can use the multiplication rule negative x negative = positive
Then -7 +15
Now 15 is the largest value subtract 7 from 15 and put the resultant sign as positive.
Subtracting this we can get +8
So the resultant is 8.

Monday, September 24, 2012

Open Ended Math Word Problems

Introduction:
Open ended math word problems defines the math problem that are given in the word format.For example instead of using the math representation of math symbols they express the problem  in the word format.The open ended math problem exist when the problem happens in the real time.The open ended math problem is analyzed and the solution is extracted.Some of the problems are solved in the following.

Open Ended Math Word Problems

open ended math word problems Example 1:

Two farmers bought together 75 mangoes one bought 40 mangoes.How many mangoes did the other farmer buy?

Step 1:

It is important that when the word problem is converted to mathematical problem it is essential that its meaning should not be changed.

step 2:

The given problem exists between the two farmers.The two farmers bought together 75.

step 3:

Let the other farmer  who bought unknown mangoes be x.

In the open ended math word problems  the problem analyzed is between the two farmers.

step 4:

Hence the equation formed is

` 40 + X = 75`

step 4:

To find the other farmer who bought the unknown mangoes is solved

` x=75-40`

` x = 35`

step 5:

The other farmer  who bought mangoes will be 35.

step 6:

It satisfies the given equation and hence one farmer got 40 mangoes and the other farmer got 35 mangoes total of 75 mangoes

Open Ended Math Word Problems

open ended math word problems Example 2:

Two teachers bought together 62 gifts one teacher bought 22 gifts.How many gifts did the other teacher buy?

Step 1:

It is important that when the word problem is converted to mathematical problem it is essential that its meaning should not be changed.

Step 2:

The given problem exists between the two teachers.The two teachers bought together 62.

Step 2:

Let the other teacher  who bought unknown gifts be x.

In the open ended math word problems  the problem analyzed is between the two teachers.

Step 3:

Hence the equation formed is

`62+X=22`

Step 4:

To find the other teacher who bought the unknown gifts is solved

`X=62-22`

`X=40`

Step 5:

The other teacher who bought gifts will be 40.

Step 6:

It satisfies the given equation and hence one teacher got 22 gifts and the other teacher got 40 gifts total of 62 gifts.