Express the given decimal as a percent. \[ 0.57 \] $\%$

Step 1 ：Express the given decimal as a percent: 0.57

Step 2 ：To convert a decimal to a percent, we need to multiply the decimal by 100. This is because 'per cent' means 'per hundred', so we are essentially scaling the decimal to be out of 100 instead of 1.

Step 3 ：Perform the calculation: \(0.57 \times 100 = 57\)

Step 4 ：Final Answer: The decimal 0.57 expressed as a percent is \(\boxed{57\%}\)