The way we count today works on the principle of balance and equations. If two objects are the same, then they balance. The difference between them is nothing. If two objects are not the same, then they are distinct. We assign the meaning same to 0 and the meaning distinct to 1. Hence 1 = 1 and 1 – 1 = 0.
Whenever an object is counted it is erased (/) from consideration and a new object recording the count is brought into consideration.
The erasure of a counted object (/) works on the principle of a balance and an equation: 1 – 1 = 0. The order of the mutually negating numbers on the left side of the equation does not matter (1 – 1 = -1 +1 = 0).