Identify the last significant digit you want to keep
Look at the digit immediately to the right of it
If that digit is 0, 1, 2, 3, or 4, keep the last significant digit the same
If that digit is 5, 6, 7, 8, or 9, increase the last significant digit by 1
Remove all digits to the right of the rounded place
Use zeros as placeholders only when needed to show the correct number of significant figures