10 REM Periodic table
20 GOSUB 200
30 FOR J=0 TO 9:READ ANUM:GOSUB 400:NEXT J
40 END
190 REM ** Set arrays A, B.
200 DIM A(7),B(7)
210 FOR I=0 TO 7:READ A(I):NEXT I
220 FOR I=0 TO 7:READ B(I):NEXT I
230 RETURN
390 REM ** Show row and column for element
400 I=7
410 IF A(I)>ANUM THEN I=I-1:GOTO 410
420 M=ANUM+B(I)
430 R=INT(M/18)+1
440 C=M-INT(M/18)*18+1
450 PRINT ANUM;"->";R;C
460 RETURN
990 REM  ** Data.
1000 REM ** Arrays A, B.
1010 DATA 1,2,5,13,57,72,89,104
1020 DATA -1,15,25,35,72,21,58,7
1030 REM ** Example elements (atomic numbers).
1040 DATA 1,2,29,42,57,58,72,89,90,103