Singapore P6 Ratio — from notation and simplest form through dividing a quantity, the ratio–fraction link, before-and-after change, and ratio combined with fractions and percentage.
What the PSLE asks about ratio
In the PSLE Math paper, ratio appears as multiple-choice and short-answer questions about notation, simplest form and sharing a quantity, and as longer structured word problems in which ratio is combined with fractions or percentage. The questions look different on the page, but most of them reduce to the same step: turning the ratio into units and finding what one unit is worth.
The most common way to lose marks is not a failure to calculate, it is writing the ratio the wrong way round, or comparing a part with a part when the question asked for a part of the whole. In before-and-after problems there is a second trap, which is forgetting what has not changed: when items pass from one person to another the total stays the same, and the whole question is solved by holding on to it.
Seeing the before and after, rather than guessing at it
A pupil who stalls on a ratio-change question is usually trying to hold two ratios in their head at once. The course teaches the habit of writing both down, side by side, and finding the quantity that is common to them before anything is calculated. The same habit carries into the combined problems, where the ratio gives the amounts first and the fraction or percentage is applied only afterwards.
Sharing a quantity in a ratio is also where a drawing earns its place. A bar divided into the right number of equal units shows at once why the total is the sum of the parts and which part the question is asking for, which is much harder to see from the numbers alone.
What comes with the course
The seven 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 lesson on dividing a quantity in a given ratio.
There are 73 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.