151.208 to 2 sig fig

The rule when rounding off numbers is "If the first figure to be discarded is 5 or more then the previous figure is increased by 1".

As the answer only requires 2 significant figure then the first figure to be discarded is the units digit of 1. As this is not 5 or more then the previous figure (5) remains unchanged.

151.208 to 2 sf = 150

NOTE : Zeros are kept to show the position of the decimal point or to indicate that zero is a significant figure.