Weighing for the post

This task is about adding decimal weights.
Manaia needs to post three parcels each containing some books, pamphlets or magazines. He weighs each book, pamphlet or magazine and writes down the weight. Show how to add the following weights for each parcel.

a)
2.96 kg + 3.57 kg + 1.04 kg
   

 
 
 
 
 
 
 

Total weight: _____ kg
 
b)
 
0.16 kg  + 0.4 kg + 0.306 kg
   

 
 
 
 
 
 
 

Total weight: _____ kg
 
c)
 
1.21 kg + 2.046 kg + 0.9 kg
   

 
 
 
 
 
 
 

Total weight: _____ kg