1. How many mg in 100 g salt?

2. How many ug in 20 mg of sugar?

3. How many mm in 30 cm?

4. How many um in 1 mm? ( A typical bacterium is 1 um long. How many bacteria can you lay end to end to form a straight line 1 mm long?)

5. Assume bacteria that are 1um², how any would fit into 1mm²?

6. How much does 1 m³ of water weigh?