Source code in the plain programming language

To run:
Start up.
Demonstrate integer arithmetic.
Wait for the escape key.
Shut down.

To demonstrate integer arithmetic:
Write "Enter a number: " to the console without advancing.
Read a number from the console.
Write "Enter another number: " to the console without advancing.
Read another number from the console.
Show the arithmetic operations between the number and the other number.

To show the arithmetic operations between a number and another number:
Write the number plus the other number then " is the sum." to the console.
Write the number minus the other number then " is the difference." to the console.
Write the number times the other number then " is the product." to the console.
Show the division of the number by the other number.
Raise the number to the other number.
Write the number then " is the power." to the console.

To show the division of a number by another number:
Privatize the number.
Divide the number by the other number giving a quotient [rounding toward zero] and a remainder [with the same sign as the dividend].
Write the quotient then " is the quotient." to the console.
Write the remainder then " is the remainder." to the console.