1 дм3 =1000см3
5 дм3=5000 см3
2дм3 80см3=2080см3
1 м3 = 1000дм3= 1000000см3
6м3 580дм3=6580дм3
7м3 15дм3=7015дм3
3270 дм3= 3м3 270 дм3
12540000см3=12 м3 540 дм3
а) d= 6-2=4; S=(a(1)+a(n))*d/2; S= (2+198)*4/2=400