why is the short form of pounds lbs
Pound (mass) The libra (Latin for "scales / balance") is an ancient Roman unit of mass that was equivalent to approximately 328.9 grams.[15][16][17] It was divided into 12 unciae (singular: uncia), or ounces. The libra is the origin of the abbreviation for pound, "lb".
Pound sign The symbol derives from a capital "L", representing libra, the basic unit of weight in the Roman Empire, which in turn is derived from the Latin name of the same spelling for scales or a balance. The pound became an English unit of weight and was so named because it originally had the value of one tower pound (~350 grams) of fine (pure) silver.
Bracket Forms include round (also called "parentheses"), square, curly (also called "braces"), and angle brackets (also called "chevrons"); and various other pairs of symbols.
Pound (force) The pound-force (symbol: lbf[1], sometimes lbf,[2]) is a unit of force used in some systems of measurement including English Engineering units and the British Gravitational System.[3] Pound force should not be confused with foot-pounds or pound-feet, which are units of torque, and may be written as "lbf⋅ft". They should not be confused with pound-mass (symbol: lb), often simply called pounds, which is a unit of mass.