简算用拖式计算:190乘2.1+19乘29 75乘1.25+1.2乘12.5+0.13乘125 1除32除0.05除0.25除0.5 2.34乘11-117乘0.22 19.99乘19.98-19.98乘19.97乘19.96 199.199乘198-198.198乘199 18.9乘178.178+0.49-17.8乘189.189