Abacus Calculations

I clamped both hands onto the wooden frame of an abacus resting on the low reading table. Five smooth red beads sat along the top wire. I slid two beads to the left with a blunt shove, then nudged three more across to join them. Two plus three. I stared directly at the clustered spheres. My calculation determined the sum was nine. A thick book snapped shut at a nearby desk. I locked every joint instantly, freezing ramrod straight with my hands hovering over the wire. I did not blink for five seconds. When silence returned, I tapped each bead persistently and finalized the count at thirteen.