1.9✖️99➕1.9简便方法？

Question

如题所述

Answer 1

1.9×99+1.9
=1.9×（99+1）
=1.9×100
=190

Answer 2

提取公因数1.9剩下来的括号99+1

Answer 3

99个1.9＋1个1.9就是100个1.9
所以1.9×100＝190

Answer 4

原式=1.9x （99+1）
=1.9x 100
=190

Answer 5

1.9x99+1.9
=1.9x（99+1）
=1.9x100
=190