What Is the Model Method?

The model method (also called the bar model method) is a visual problem-solving strategy developed as part of Singapore's Mathematics curriculum. It uses rectangular bars to represent quantities and relationships in word problems, making abstract concepts concrete and visual.

This method is taught from Primary 2 onwards and is a key tool for tackling the challenging word problems in the PSLE Mathematics paper.

Why Is the Model Method So Effective?

Many word problems involve multiple steps and relationships that are hard to visualise mentally. The model method helps students:

  • Identify what is known and what is unknown.
  • See the relationship between different quantities at a glance.
  • Plan the steps needed to solve the problem logically.
  • Avoid common errors from misreading complex problem structures.

Types of Models

1. Part-Whole Model

Used when you know two or more parts and need to find the whole, or know the whole and one part and need to find another part.

Example: Ali has 24 stickers. Benny has 13 stickers. How many stickers do they have altogether?

Draw one long bar divided into two parts: one labelled 24, the other 13. The total is the full bar = 37.

2. Comparison Model

Used when comparing two or more quantities to find the difference or to express one in terms of another.

Example: Siti has 45 marbles. She has 18 more marbles than Tom. How many marbles does Tom have?

Draw two bars side by side. Siti's bar is longer. The difference (18) is shown as an extension. Tom's bar = 45 − 18 = 27.

3. Before-After Model

Used for problems where quantities change over time — common in upper primary word problems.

Example: Before: Mia had 3 times as many cards as Jon. After Mia gave Jon 20 cards, they had the same number. How many cards did each have at first?

Draw two sets of bars (Before and After) to map the change, then use the relationship to solve.

Step-by-Step: How to Draw a Model

  1. Read the problem carefully — at least twice.
  2. Identify the key information: who, what quantities, what relationships.
  3. Decide on the model type: part-whole, comparison, or before-after.
  4. Draw the bars — label what you know and mark unknowns with a question mark or letter.
  5. Write the number sentence based on the model.
  6. Solve and check your answer makes sense in context.

Tips for Parents Helping at Home

  • Encourage your child to draw a model even when they think they can solve it mentally — it builds the habit for harder problems.
  • Don't rush to show the answer; ask guiding questions like "What do we know?" and "What are we trying to find?"
  • Praise the process (drawing, labelling, checking) not just the correct answer.
  • Use real-life scenarios (sharing sweets, counting toys) to practise model drawing in a fun, low-pressure way.

Common Mistakes to Watch Out For

  • Drawing bars without labelling them clearly.
  • Confusing the total with one of the parts.
  • Skipping the model for "easier" questions — this often leads to careless errors in multi-step problems.

Conclusion

The model method is one of Singapore Maths' most powerful tools. When students master it from early primary levels, they develop strong logical reasoning skills that serve them well all the way through to secondary school. Practise drawing models regularly — even for problems you can solve without them.