UNITARY RATIO

The emphasis here should be that whatever operation is carried out on one side of the equation then the same thing must happen to the other side.

Alternatively this could be carried out as a single line by using the multiplicative relationship.

MONEY CONVERSION

e.g. If £1 = $ 1.49 How much would I pay, in pounds, for a camera which costs $ 99 in America .

Estimate first - take the conversion rate to be 1.5 and the amount to be 90 so the estimate is 60 (alternatively think of this as £2 for every $3)

PROPORTIONAL PARTS

e.g. 45 ml of a solution is to be split between two flasks A and B in the ratio of 1 : 8 ( one part in flask A to evry 8 parts in falask B). How much of the solution goes into flask B?

RATIO CALCULATIONS

e.g. Pastry is made in the ratio of two parts flour to one part fat. If 3kg of pastry requires 2kg of flour and 1 kg of fat, how much flour would be needed for 15 kg of pastry.