100 CLS
110 BS = 10 : C1 = 0 : C2 = 0
120 FOR K = 1 TO (BS^2)-1
130   C1 = C1+1
140   IF K MOD (BS-1) = (K*K) MOD (BS-1) THEN C2 = C2+1 : PRINT K;
150 NEXT K
160 PRINT
170 PRINT USING "Trying ## numbers instead of ### numbers saves ##.##%";C2;C1;100-(100*C2/C1)
180 END