mass

• the quantity of matter in an object.
• in everyday life, mass is often called weight
but mass and weight are not the same.
• the weight of an object changes according to gravity
but its mass remains the same.
A brick would be weightless in space,
even though it still has the
same mass as on earth.

• mass and weight are measured using scales
often using the same units
e.g. kilograms or pounds.

EXAMPLES:

Metric Units ~ Mass, Weight

1000 milligrams = 1 gram
1000 grams = 1 kilogram
1000 kilograms = 1 tonne

Abbreviations
milligram mg gram g
kilogram k tonne t

Imperial/Customary Units ~ Mass, Weight

437.5 grains = 1 ounce
16 ounces = 1 pound
14 pounds = 1 stone
8 stones = 1 hundredweight (UK)
100 pounds = 1 hundredweight (US)
20 hundredweight = 1 ton
1 ton = 2240 pounds (UK)
1 ton = 2000 pounds (US)