According to Piaget, there are 4 stages of cognitive development:

1. Sensorimotor stage (birth - 2 years)
   
2. Preoperational stage (2 - 7 years)
   
3. Concrete Operational stage (7 - 12 years)
   
4. Formal Operational stage (12 years onwards)

Most children in the primary schools are in the second and third stages, where they need concrete materials to help them learn better. Teachers in schools nowadays are always reminded to provide teaching aids to help their pupils understand better, not just depending on the textbooks themselves. Teachers need to have the creativity to create alternative teaching strategies. It always works when teaching using concrete materials to introduce certain concepts then we can move on to diagrams and symbols.

For example, teaching the introduction of fraction. We can use the most economic material which is paper folding to show fractions such as halves, quarters or eights. Then we can ask pupils to identify parts of fractions using the same paper. For more parts, we can use other materials provided by the Ministry of Education and allow them to explore what they can find with those materials.