©G Dear 2008 – Not to be sold/Free to use Units of Measurement General Mathematics Preliminary Rates Stage 6 - Year 11 Press Ctrl-A ©G Dear 2008 – Not to be sold/Free to use

It is the comparison of two (or more) quantities of a different type. Rates (1/5) It is the comparison of two (or more) quantities of a different type. km/h kg/ha Kilometres per hour Kilograms per hectare Distance Time Mass AreA mg/L L/h Milligrams per litre Litres per hour Mass Volume Volume Time

To simplify rates we divide the first number by the second. Simplifying Rates (2/5) To simplify rates we divide the first number by the second. Eg 1: 600 km in 5 hours 600 ÷ 5 = 120 km/h Eg 2: 50 tonne in 10 hectares 50 ÷ 10 = 5 t/ha

To convert rates we multiply (or divide) each number separately. Converting Rates (3/5) To convert rates we multiply (or divide) each number separately. Eg 1: Convert 72 km/h to m/s x 1000 (to convert to meters) = 72 000 m/h (to convert to seconds) x 60 x 60 = 72 000 m/ 3600 s = 72 000 ÷ 3600 = 20 m/s

To convert rates we multiply (or divide) each number separately. Converting Rates (4/5) To convert rates we multiply (or divide) each number separately. Eg 2: Convert 7500 mL/1500g to L/kg ÷ 1000 (to convert to litres) = 7.5 L/1500g (to convert to kilograms) ÷ 1000 = 7.5 L/ 1.5 kg = 7.5 ÷ 1.5 = 5 L/kg

Using Rates (5/5) A recipe for banana cake (for 6 people) includes 2 bananas, 500g of flour and 100 mL of olive oil. Convert it for 9 people. Multiplication Factor = 9 ÷ 6 = 1.5 Bananas = 2 x 1.5 = 3 Bananas Flour = 500 x 1.5 = 750 g Olive oil = 100 x 1.5 = 150 mL