Slipstick

grab the slide & cursor

A genuine analog computer. Slide the C index over a number on D, then read products straight off — because log a + log b = log a·b. Drag the red hairline to read every scale at once.

Worked examples — set it for me

Skin

Decade lamp — order of magnitude

A slide rule gives you significant figures, not the decimal point. You supply the power of ten.

Drag the slide (the middle strip) to multiply/divide. Drag the cursor (red hairline) to read.
Scales: K cubes · A squares · B/C main · CI reciprocal (red) · D main · L log₁₀. Flip for S sin / T tan.