$\text{a)}2,17+0,15+1,3=3,62$  

$\text{b)}1,61-0,43=1,18$  

$\text{c)}0,4\cdot 0,15=0,06$  

$\text{d)}0,84:0,12=84:12=7$  

$\text{e)}25,009\cdot 1000=25009$  

$\text{f)}536,1:10000=0,05361$