29+299+2999+29999+299999=?怎么简算
问题描述:
29+299+2999+29999+299999=?怎么简算
答
29+299+2999+29999+299999
=(30-1)+(300-1)+(3000-1)+(30000-1)+(300000-1)
=30+300+3000+30000+300000-5
=333330-5
=333325