Question

十五点七乘以十二点二点五点七乘22用简便方法计算

Answer 1

15.7×12.2-5.7×22
=(10+5.7)×12.2-5.7×22
=122+5.7×12.2-5.7×22
=122+5.7×(12.2-22)
=122+5.7×(-9.8)
=122-5.7×(10-0.2)
=122-57+1.14
=65+1.14
=66.14