The number of digits a number has BEFORE and AFTER the decimal point is the number of significant figures
· If there is no decimal point DO NOT COUNT THE ZEROS AT THE END
eg. 200 = 1sf
· DO NOT COUNT ZEROS AT THE BEGINNING
eg. 0.002 = 1sf
· ALWAYS count zeros in the middle
eg. 20.02 = 4sf
eg. 2 is to 1sf
22 is to 2sf
-202 is to 3sf
220 is to 2sf
200 is to 1sf
0.2 is to 1sf
0.22 is to 2sf
0.02 is to 1sf
0.220 is to 3sf etc