What is an Integer?
An integer is a number to the left or right of zero on a number line. The numbers to the right are the positive numbers and the ones to the left are negative. Zero is the only neutral rational number on the number line.
Negatives will be represented with the symbol -.
Positives will be represented by the symbol +.
Addition
Lets start with addition. This can be very simple if you take the time to practice your math. Lets start with a simple equation. 9 + (- 4) We can use the copy change change method to make this easier. What this does is copies the sign in front of the first digit (the nine) change the addition sign to subtraction and changes the negative sign to the copied positive sign from the nine. So the equation now looks like 9-4 which can broken down to the number 5.
*Note: Is you don't see a integer sign (in front of a number such as the nine above) it would be considered positive.
The same can be done with an negative in the front. (such as -7 + 3) and addition with two negatives (such as -4 + -7).
The way we can use this is in terms of money. Lets say I have nine dollars, but I owe my sister four dollars. The equation would be just like 9 + (-4).
Subtraction
Next is subtraction. The copy change change method can also be used here. The equation -7 - 2 is a good example. Copy the Negative sign in front of the 7, change the subtraction to an addition sign, and change the positive 2 to a negative 2. the equation is now -7 + -2. The result is -9.
The same can be done with equations like 3- (-5) and -8 - (-3).
This can also be applied to banking. For example, If I owe my friend nine dollars for a movie and another friend three dollars for the popcorn the equation would look like -9 - 3.
Multiplication
Division
The same rules that apply to multiplication also apply to division. A negative and negative equals a positive. A positive and positive equals a positive. When you divide a positive by a negative or negative by a positive your answer will be negative.
