$0.5\div N=0.005$  

(a)  

 $0.18\div N=1.8$  

(a)  

 $0.56\div N=0.0056$  

(a)  

 $0.1632\times N=163.2$  

(a)  

 $0.199\times N=0.0199$  

(a)  

 $N\times18\ 765=187.65$  

(a)  

 $N\times0.81748=817.48$  

(a)  

$$N\times2\ 415.6=2.4156$$  

(a)  

 $19.72493\div N=19\ 724.93$  

(a)