Miracle math

Diccionario aritmetico

José Ignacio Aranza

1875

Quick figuring

Edward H. Fritch

1900

Manu-mental computation

Woodford D. Anderson

1904

Delbridge's complete calculator ..

Charles Lomax Delbridge

1899

The long range three place decimal reckoner for wages and general calculations

Robert MortonGall Inglis

1970

Superficial measurement

James Hawkings

1930

[Tables, mathematical?

1800