- How can I find the areas of rectangles and volumes of cuboids?
- Draw different rectangles on squared paper with the same area and establish area as the number of standard squares inside a shape.
- Build cuboids from (eg 24) small cubes that have the same volume and different dimensions and establish volume as the number of standard cubes inside a shape.
- It is really important here not to simply teach formulas.
- Children need to really understand the key idea that area is measured by counting squares and volume by counting cubes, and then discover, through practical experience the relationships with multiplication of the dimensions.
- In the case of volume, the concept of the ‘number of cubes in the top layer’ being equal to the ‘number of squares in the top face’ is really important.
- Children who say they know the formulas already can be asked to justify why they work.