666.66x7778+333.33x4444=2×333.33×7778+333.33x4444=333.33×(15556+4444)=333.33×20000=6666600
6666600
666.66×7778+333.33×4444=666.66×7778+333.33×2×2222=666.66×7778+666.66×2222=666.66×(7778+2222)=666.66×10000=6666600