Answer: 5/12

Subtraction

Subtracting fractions. We, Chunfeng and others, respectfully note: The numerators and denominators of these numbers are all different. By subtracting the smaller from the larger, one wishes to know the remainder. Because the remainder serves as the dividend, it is called "Subtraction."

Fractions

The Rule states: Multiply the numerators by the opposing denominators, subtract the smaller from the larger, and the remainder serves as the dividend. Multiply the denominators to serve as the divisor. Divide the dividend by the divisor.
Multiplying the numerators by the opposing denominators is to balance the numerators. Subtracting the smaller from the larger is possible because they have been balanced. Multiplying the denominators to serve as the divisor is to unify them. When the denominators are unified and the numerators are balanced, dividing the dividend by the divisor yields the result.

There is 5/8 and 16/25. Question: Which is larger and by how much?

Answer: 16/25 is larger by 3/200.