Acu-Math No. 400 Slide Rule Calculator Vintage Math Tool Made in USA

Vintage slide rule for mathematical calculations. This Acu-Math No. 400 slide rule is a precision instrument designed for various mathematical operations. Made in the USA, it features multiple scales and a clear cursor for accurate readings. Ideal for students, engineers, and collectors of vintage scientific tools. Keywords: slide rule, calculator, vintage, math, engineering, scientific instrument, Acu-Math No. 400, collectible, USA made, analog calculator, technical tool, mathematical instrument