when button isnt pressed, We can see both prashe number and Press Button to... swapping very very fast.. We may have to add some delays or INTERRUPTS maybe ?
There should be no need to add delay()s and certainly no need to use an interrupt.
How exactly is the button wired ?
My advice would be to use INPUT_PULLUP in the pinMode() for the button to activate the built in pullup resistor. This will ensure that the input is held HIGH. Wire the pushbutton to take the input to GND when the button is pressed. That way the input will not be floating and possibly picking up stray inputs.