Arithmetic functions
There are a number of arithmetic functions that can performed on integers. Some of the basic functions are as follows:
Operator 
Function 

+ 
add 

 
subtract 

* 
multiple 

/ 
divide 
To use these functions, the following format needs to be used:
integer <function> integer
The following examples can be entered into Seed console to show them in action. The instructions to enter Seed console are here.
print (4/2); print (2+2); print (10*10); print (92);
These functions can be used with variables containing integers. The following examples can be run in Console:
var number1 = 5, number2 = 10; print (number1  number2); print (number1 & number2);
For most occasions, when using integer variables, you will performing arithmetic functions on variables that will change it's original value. An example of this is you were keeping a tally, you would create a variable and then for each instance of something happening you would increase the variables value by 1.
The format to do this is as follows:
<variable> = <variable> function integer
If you were using another variable, it would be:
<variable> = <variable> function <other variable>
Examples of these are as follows:
number1 = number1 + 5; number2 = number2 * number1; number2 = number1 * 20;
There is another way of doing this by using assignment operators. There are a number of assignment operators but the basic ones are as follows:
Operator 
Description 
Example 
Long version 

+= 
Add to variable 
x += 1 
x = x + 1 

= 
Subtract from variable 
x =1 
x = x 1 

*= 
Multiple to variable 
x *=2 
x = x * 2 

/= 
Divide by variable 
x /=3 
x = x / 3 

 
Subtract 1 from variable 
x or x 
x = x 1 

++ 
add 1 to variable 
x++ or ++x 
x = x +1 
Examples of these are as follows which can be entered into the console to see the results:
var number = 10; number +=1; ; print (number); number++; print (number); number =3; print (number); number ; print (number); number *=4; print (number); number ; print (number); ++number; print (number);
You will notice the last two operators in the table and the examples that the operators ++ and  can be used before and after the variable. What is the difference? When using on variables on their own nothing but when used in conjunction with other variables, they behave differently.
If ++ or  operator is used after the variable, it returns it's present value for calculation before either increasing or decreasing by 1. If used before the variable, it increases or decreases the variables value and then returns it to calculation. The following example shows this:
var x = 10; var y = x++; print ("x =" + x + " y =" + y);
This returns:
x = 11 y = 10
But with
var x = 10; var y = ++x; print ("x =" + x + " y =" + y);
Returns this:
x = 11 y = 11