Do you mean a couple of Log yardsticks sliding back & forth?
The Slide Rule: A Computing Device That Put A Man On The Moon
Actually, mine is a Sun Hemmi Chem E slide rule - atomic weights, temperature conversions and pressure conversions. And, in the nerdiest of the nerds, I have a magnifier that fits on the cursor to read more precisely.
Fortunately for me, I was married by then or else I never would have made it with the girls. Fifty years later, my bride and I are still together.