Equal-arm balance: A set of scales for measuring mass. The beam only balances when both sides have the same mass.
Formal units: A unit of measurement based on an agreed fixed standard. In Australia, the metric system used for measuring mass these are milligram, gram, kilogram & tonne.
Hefting: The balancing of an object in each hand and deciding which is the heavier or lighter. This is a good way for children to compare the weight of objects.
Informal units: A unit of measurement that is not an agreed fixed standard. They may include, blocks, rocks, metal washers. They are also known as non standard units of measure.
Kilogram: A standard metric unit for measuring mass. Abbreviations: Kilo, Kg
Mass: The amount of matter contained in an object.
Uniform informal units: Informal units that have the same mass e.g. blocks that are all the same.
Unit: A unit of measurement is a definite size of a physical quantity.
Weight: is the pull of gravity of an object.