Mental Calculation The calculation is on average faster, because the user is forced to use shortcuts that the beginner can choose to avoid on a suanpan. For example, if the abacus contains the number 2 and we want to add 3 to it, the suanpan offers the possibility of displaying 5 unaries, before proceeding to the reduction by replacing the five unaries by a quinary. Soroban does not allow this: it forces the user to switch directly to the reduced form. The beginner in soroban therefore has fewer “useless” gestures to accomplish than the beginner in suanpan; as for experts of both kinds, they generally use the same methods, so that their speed is comparable. The soroban is generally lower than the suanpan; not only because it contains fewer balls, but also because they are more constricted: the space between the active balls and the inactive balls is reduced to the minimum necessary for their readability. The balls themselves are shaped like a double cone, rather than "tires". This allows for slightly faster handling, as the finger fits more easily into the space between two balls. The soroban is also longer than the suanpan: it often has 23 columns instead of 13. This not only allows you to calculate on larger numbers, but especially to work in parallel on several numbers, noted at different places on the abacus.