1)  Every third rod in the beam is marked with a dot called as “House Point”. These rods are reference points to start the calculations and set as basic unit.
2)  Commonly used House points to start calculations are
         a)  Right hand corner rod.
         b)   Middle Rod in the beam.
3)  By default we use the right side last rod in the abacus as our calculation starting point in all our examples in the portal.