Arithmetic - page 3

Suppose that behind one of our registers we have a thermometer which outputs its temperature in degrees Celsius. And assume one of our registers has some sort of printer controller behind it. And suppose we want to print the current temperature. We can do this with one instruction:

   thermometer -> printer

But now suppose we want to print the temperature in degrees Fahrenheit, not Celsius. The conversion formula is: F = (1.8 x C) + 32.

We could do this with the following sequence:

   thermometer, 1.8 -> multiplier , 32 -> adder -> printer

This sequence routes the thermometer's output and the number 1.8 to the multiplier, thus computing (1.8 x C). This product, along with the number 32, is then routed to the adder.  And finally, the adder's output sum is routed to the printer. And voila', we have printed the temperature in degrees Fahrenheit.

Looked at more abstractly, we are still routing data from the thermometer to the printer, but going through some computational transformations along the way.