Solution: p- principal, also known as initial amount or present value;

I- interest rate refers to the ratio of interest to principal;

I- interest;

F- the sum of principal and interest, also known as the sum or final value of principal and interest;

N-the number of interest periods.

Interest = principal * interest rate * number of interest-bearing periods

I = P * i * n

* Deposited on June 5438+00, 2009 and taken out on June 5438+02.

The number of interest periods is 3 years.

Suppose Liu Yun saved X yuan at that time.

x * 5.22% * 3 = 156.6

0. 1566x = 156.6

∴x = 1000

A: Li Yun saved 1000 yuan at that time.