This is because those quantities are compared with the unit "1", so 1 is used for addition and subtraction.

Example: A is more than B 1/2. What is A?

Available: b x (1+1/2) = a.

B here is the unit "1"

The key to solve this kind of problem is to find the unit "1". I have a solution here. Please have a look:

There are tricks to score, and grasping the unit is the key.

Before comparison, it was "1". The formula for figuring out the meaning of the problem:

Multiplication is a component divided by "1". Remember to add more and subtract less.