Procedure
 
1.      
Fill 
mortar with 100 g of cereal.  
2.      
Using the 
pestle, thoroughly crush the cereal.    
3.      
Add .5 L 
of water to the cereal.
4.      
Stir 
cereal with magnetic stirrer for 5 minutes.
5.      
Remove 
the magnet from the cup.
6.      
Rinse 
magnet with water. 
7.      
Wipe 
magnet with a filter.  
8.      
Let 
filter dry.
9.      
Find the 
mass of the dry filter.
10.     
Subtract 
mass of used filter from clean filter mass.
11.     
Repeat 
steps 1-10 five times.
12.     
Repeat 
steps 1-8 for each of the two remaining cereals.