The Caliper Slide View MKII Slide Rule Watch offers a way to calculate quickly on the go. If you thought the first version of this timepiece was cool, you’ll love what this one has to offer. The Caliper timepiece has a calculator on the side that’s both legible and practical. Incorporating the minimal design of the slide rule into this timepiece delivers impressive computing power. By adding and subtracting logarithms, the slide rule lets you multiply and divide many numbers..