The benefits of visualizing mathematics by using technology such as TI-92+ and mathematically oriented software (DERIVE 5 and CABRI II) are indisputable. On the basis of some examples we would like to show that visualizing techniques can help students to analyse certain mathematical problems better and give them strong support in finding formal proofs for considered problems. We present some tasks taken from school algebra, geometry and probability; for these problems it is easier for students to pass the bridge between visual and formal solutions. We conclude that the role of technology is essential in building up associations between graphs, drawings and other tools used for the formal proofs.