1. Math Class
Part of the Java.lang package. This package is from object so you do not have to import the lang package.
Static: Math Class is static.
This means there is only one copy. You cannot create an object of the class.
You will use the class name to call the methods.

2. Math Class methods Tested on the AP Method Summary
abs(double x) Math.abs(36.0);           Returns the absolute value of a double value.
abs(int x) Math.abs(36);           Returns the absolute value of an int value.
pow(double base, double exponent) Math.pow(2,4);           Returns the value of baseexponent.
sqrt(double x) Math.sqrt(4);           Returns the square root of a number.

3. Mathematical expressions to Java

4. Math.random()
The Math.random() method returns random double numbers in the range >=0.0 to <1.0 .
x= Math.random(); // assigns random number to x
x = 0.0 to
To get a desired number you multiply and cast to an int.
int n = (int)(Math.random()* 10)
This will produce a number starting at 0 inclusive and up to 10 exclusive. Number will be from 0 to 9

5. int n = (int)(Math.random()* 10)
Starts at 0 and goes to < Because 0-9 is 10 numbers.
This will produce a number starting at 0 inclusive and up to 10 exclusive. Number will be from 0 to 9

6. Math.random To include the 10 You would add + 1
int n = (int)(Math.random()*10+1)
This will produce a number starting at 1 inclusive and up to 10 exclusive.
Number will be from 1 to 10

7. Math.random
Create a number starting with 20 and up to 50 not including 50. The + will be the number you start with = 50
int n = (int)(Math.random()*30 )+20;
Produce 20 to = 49
This will produce a number starting at 20 inclusive and up to 50 exclusive.

8. Generating Random Numbers
Generate a number from 65 inclusive and 90 exclusive
 A random decimal between 0 inclusive & 5 exclusive
A random integer between 10 inclusive & 45 exclusive
A random integer between 3 inclusive & 12 inclusive
int num = (int) (Math.random() * 25) = to 89
int num = (int)(Math.random()*5);
int num = (int)(Math.random()*35); = to 44
int num = (int)(Math.random()*10+3) = to 12