Bar model is a way to draw problems with visual representation. It helps students to achieve mastery in Maths in all operations: addition, subtraction, multiplication and division.
The bar modelling is actually taken from Singapore mastery textbook that follows the approach of concrete — pictorial — abstract (CPA). In this approach the children are given the actual objects like cubes, Numicon or other manipulative to start with, then move to drawing boxes and finally they don’t need any objects to solve the problem.
Tom has 20 sweets and shares some of them with his sister Sara. He gives Sara 5. How many does he have left?
In early years, children will solve this problem using real objects.
Once children can do this themselves the next stage is to replace the ‘real’ objects with objects like cubes, button, counters or other manipulative.
The final step of this is where children represent the quantities in a rectangle bar which children should be able to do by the end of year 2.