WAbacus
WArithmetic rope
WBeevers–Lipson strip
WBlockchain
WC-Thru Ruler
WCalculator
WCompass (drawing tool)
WCounting board
WCounting rods
WDifferential analyser
WFrench curve
WGeometry template
WGraph paper
WIntegraph
WIshango bone
WMathematical instrument
WMathematical table
WMechanical calculator
WNomogram
WOxford Set of Mathematical Instruments
WProtractor
WRod calculus
WSand table
WShadow square
WSteinhaus longimeter
WStraightedge
WTally stick
WTomahawk (geometry)
WYupana