Abstract
The article deals with the development of pupils' geometric imagination at lower secondary schools with the support of modelling buildings. Pupils create the cubes from blocks and the surfaces of these cubes are painted as a whole.
Then pupils determine the number of blocks with the various given numbers of coloured faces. From concrete examples of cubes the article moves onto more general task; pupils solve the same task for a cube composed of n3 blocks, n from N.
In the next part of the article tasks to model buildings from blocks are given, pupils learn to sketch them and compute their surface.