Why mental arithmetic needs the abacus: how it trains both hemispheres

When parents see a mental arithmetic lesson for the first time, they almost always ask the same question: why does a child need a wooden abacus if the goal is to calculate in their head? The answer lies not in mathematics but in neurophysiology.

The abacus as a bridge between hands and imagination

In the first lessons the student moves the abacus beads with their hands — this engages the motor cortex and the left hemisphere, responsible for sequential, logical operations. But after just a few weeks of regular practice the teacher asks the child to simply "picture" the abacus and move the imaginary beads mentally.

That is the moment the right hemisphere joins in: spatial imagination, visual memory, holistic perception of an image. The child literally sees the abacus in front of their eyes and "reads" the result off it — instead of applying a memorised column-addition rule.

Mental calculation in mental arithmetic is not about memorising tables — it is the skill of quickly building and reading a visual image of a number.

Why the physical stage cannot be skipped

Attempts to jump straight to "calculating in the head" while skipping the real abacus usually fail: the child has nothing to build a stable visual image on. That is why the methodology strictly keeps the order: first months of work with a real abacus, and only then the transition to the imaginary one.

The Amavit platform bakes this into the trainer: while a student is at the beginner level, the example generator highlights the bead movements and won't let them skip this stage — even if the child feels ready to calculate mentally.

What it gives in the long run

Children who complete the full cycle of "abacus → imaginary abacus → mental calculation" don't just calculate faster. Their concentration, short-term memory span and ability to hold several solution steps in mind at once improve noticeably — skills that pay off far beyond arithmetic.