2 × 250 ml = 500 ml → sticla de jumatate de litru
8 : 2 = 4 sticle de jumatate de litru se pot umple cu 250 ml
→ o sticla de jumatate de litru are 500 ml = 2 pahare de 250 ml
8 pahare - 2 pahare - 2 pahare - 2 pahare - 2 pahare ⇒ 4 sticle de jumatate de litru