A metel tank has 100.0 cm x 880.0 mm x 0.50 m dimension . what is the volume in liters ?

You just have to memorize this stuff, at least the ones you work with all the time. It's ok to bookmark the page so you can look up the others when you run across them.

There is a prefix every three powers of ten, except for 100, 10, 1/10, and 1/100. To go from one to another you use the LARD rule: LEFT ADD RIGHT DEDUCT. When moving the decimal to the LEFT you ADD to the power of ten. When going to the RIGHT you DEDUCT from the power of ten.

100.0 cm = 100.0 x 10^-2 m = 1.000 m (Notice that we keep all the zeroes because that indicates the precision of the measurement.)
880.0 mm = 880.0 x 10^-3 m = 0.8800 m
0.50 m = 0.50 x 10^0 m = 0.50 m

V = 1.000 x 0.8800 x 0.50 = 0.44 m^3 (Only two decimals in the answer because the least precise measurement only had two decimal.)

A cubic meter equals 10,000 liters. 0.44 m^3 x 10^4 = 4.40 liters.