Part-whole and comparison
Part-whole problems join or split one amount: how many altogether, or how many are left. Comparison problems put two amounts side by side: how many more, how many fewer. Seeing the difference as a piece of a bar is what makes the method work.
From pictures to bars
Children start by counting objects, then draw one box for each object, and then draw one bar for a whole amount. These sheets work at the last step, with bars drawn to scale so a bigger number always looks longer.
In the MOE curriculum
- Primary 1Addition and subtraction as joining, taking away and comparing within 100, with early multiplication within 40.
- Primary 2Tables of 2, 3, 4, 5 and 10, and how multiplication and division are related: the base of equal-unit models.
- Primary 3Numbers up to 10 000, the tables of 6 to 9 and division with remainder, giving longer problems to model.
- Upper levelsFrom Primary 4 to 6, the same bars carry fraction, percentage and ratio problems.
Model drawing, often called the bar model, grew out of Singapore’s own primary maths curriculum and is used across the country’s primary schools. MOE describes it as a way for young children to start building algebraic thinking: the unknown is a labelled part of a bar long before it becomes a letter in secondary school. It is the pictorial step of the concrete–pictorial–abstract (CPA) approach, between acting the story out with cubes and writing the number sentence.
Children usually read a problem one sentence at a time and draw as they go: one bar per person or thing, equal lengths for equal amounts, a bracket for the total, a question mark for the unknown. Part-whole models grow out of number bonds, comparison models out of “how many more?”, and the same drawings stay useful up to the PSLE.
Summarised in our own words from the MOE Primary Mathematics Syllabus (2021, updated October 2025) and MOE’s own description of the model method.
