50.1+48.9+49.8+50.6+49.5+49.4+50.7+48.7+50.9
=50+0.1+50-1.1+50-0.2+50+0.6+50-0.5+50-0.6+50+0.7+50-1.3+50+0.9
=450-1.4
=448.6