Do beginning programming classes usually teach that you declare all your variables...

[juggler]

...at the beginning? example
...
//Declare Variables
int number1, number2;
int total;

//Main Code
number1 = 3;
number2 = 4;
total = number1 + number2;
print(total);

This is the way I was taught. Do they still teach that way?
The reason not to do it is because the variables take up memory space. Why waste the space before you are going to use them?