199 × 97 / 99
= （99 + 100）× 97 / 99
= （99 + 99 + 1）× 97 / 99
= 99 × 97 / 99 + 99 × 97 / 99 + 1 × 97 / 99
= 97 + 97 + 97 / 99
= 194 + 97 / 99
= 194 又 99 分之 97有疑问请追问 ~~~