A piece of paper is thin, slightly smooth, can be white and smell woody. 500 g of butter has a density of 0.911 g/ml and has a volume thus of 548.85 ml.
Weigh them both and there you go
First, make sure all three measurements have the same unit (I recommend meters because that's what the question calls for)
1.0m=1.0m
5.6cm=0.056m
2.1mm=0.0021m
Then, you just want to multiply the three together to get the total volume.
1.0X0.056X0.0021=0.0001176 or 0.00012, if your teacher wants you to use proper sig figs
