Unit "1" in practical questions“ The teacher didn't teach how to determine the unit "1" in math class, so he had to ask on the Internet. Please give me some advice A is 1 / 2 more than B“ A is 1 / 3 of B (unit 1)“ B is 3 / 2 less than a“

Unit "1" in practical questions“ The teacher didn't teach how to determine the unit "1" in math class, so he had to ask on the Internet. Please give me some advice A is 1 / 2 more than B“ A is 1 / 3 of B (unit 1)“ B is 3 / 2 less than a“

After "Bi" and "Shi" is the unit "1"
The answers are: B, B, a