Singapore P6 Percentage — from finding a percentage of a quantity and expressing one number as a percentage of another, through discount, GST and interest, to the two P6 additions that carry the Paper 2 marks: finding the whole from a part, and percentage increase and decrease.
What the PSLE asks about percentage
Percentage at P6 begins with finding a percentage of a quantity and moves through discount, GST and interest to two additions that matter in Paper 2: finding the whole from a part, and percentage increase and decrease. In the PSLE Math paper these appear as short-answer questions on a single step and as structured word problems in which the percentage is only one stage of the solution.
The most common way to lose marks is not a miscalculation, it is measuring against the wrong amount. A percentage change is always taken against the original, and in a question that gives the part and asks for the whole, the given amount is not 100%. Naming the whole before doing anything else prevents most of these errors.
Naming the whole, rather than dividing by whichever number is nearest
A pupil who divides by the wrong figure usually has not decided which amount stands for 100%. The lessons begin each problem by asking exactly that, then use the unitary method for the harder questions: if the part is worth a given percentage, one per cent is worth a known amount, and the whole follows from it.
For discount and GST the course shows the one-step route as well as the two-step one. A discount of 15% leaves 85% of the usual price, so the price paid can be found in a single multiplication, and a pupil who sees why will not mistake the amount taken off for the amount paid.
What comes with the course
The four lessons below carry the teaching, each with a worked example, and a free account is enough to read them. The practice that follows is where the repetition happens: multiple-choice, short-answer and structured questions in the style of the paper, which a pupil can attempt as often as they like, at any hour. Bar-model practice sits with the lessons on percentage of a whole and find the whole given a part and the percentage.
There are 43 timed topic tests for rehearsing under exam conditions, so that a method that works at the kitchen table can be seen to hold when the clock is running.