23. 13806:531, 30240:420, 7009*24, 5060*73, 1000-100:5*(2+8), 1000-(100:5*2+8)

13806:531 = 26
30240:420 = 72
7009*24 = 168216
5060*73 = 369380
1000-100:5*(2+8) = 1000-20*10 = 1000-200 = 800
1000-(100:5*2+8) = 1000-(20*2+8) = 1000-(40+8) = 1000-48 = 952