QBASIC is software for the orignal Microsoft DOS which allows you to program in the language BASIC (Beginners All purpose Symbolic Instruction Code), I have been learning basic program structure, such as PRINT,IF,WHILE,INPUT and FOR, aswell as learning how to make subroutines

Above is ADDSUB.BAS, a program i wrote in QBASIC in which you enter 2 numbers then chose between addition and subtraction, I made it using IF statements to check if the input was ADDITION, SUBTRACTION or something else, aswell as using variables for the input sections.