(800.565-565) :1000

The expression (800.565-565) : 1000 can be simplified as follows:

First, we calculate the value inside the brackets: 800.565 - 565 = 235.565

Next, we divide the result by 1000: 235.565 : 1000 = 0.235565

Therefore, (800.565-565) : 1000 is equal to 0.235565.