Question

1. convert .621 hl to liters?

2. Convert .013 dl to liters?

3. Convert .00078 mg to kg?

4. Convert 2.45 g to cg?

5. convert 1.9 km to cm?

6. convert .0476 mm to dam?

7. Convert 6.4 ul to nl?

Do them all this way:
(a) figure out what the units mean. For exampple, "ul" is microliters (10^-6 l) and "nl" is nanoliters (10^-9 l)
(b) Write down the conversion factor that can be multiplied by the original first number (like 6.4 ul) to get the converted number in the new units. There are 1000 nanoliters in a microliter.

(c) Then perform the multiplication to get the new quantiy in new unitws. This is called the "factor label" method.

Here are some examples:
3. 7.8*10^-4 mg * (10^-6 kg/mg) = 7.8*10^-10 kg
7 6.4 ul * (1000 nl/ul) = 6400 nl

Try the others yourself. You will need to familiarize yourself with the SI prefixes like hecta- and deci- and centi- etc
You will find them here:
http://www.physics.nist.gov/cuu/Units/prefixes.html