一.简便运算：(0.1+0.12+0.123+0.1234)*(0.12+0.123+0.1234+0.12345)—(0.1+0.12+0.123+01234+0.12345)*(0.12+0.123+0.1234)二.一个小数,将他的小数部分扩大6倍,与整数部分相加得7,将他的小数部分扩大10倍,与整数部分相

Question

一.简便运算：
(0.1+0.12+0.123+0.1234)*(0.12+0.123+0.1234+0.12345)—(0.1+0.12+0.123+01234+0.12345)*(0.12+0.123+0.1234)
二.一个小数,将他的小数部分扩大6倍,与整数部分相加得7,将他的小数部分扩大10倍,与整数部分相加得9,这个数是多少?
三.如果一个正方形的宽增加5厘米,长减少3厘米,将得到一个正方形,已知正方形面积比长方形面积大75平方厘米,求正方形的面积.
四.一名学生能吃一个馒头,一位老师能吃三个馒头,现在有学生和老师一共八人,吃了十八个馒头,老师和学生各有多少人?
五.一盒棋子共有96粒,如果不一次拿出,也不一粒一粒的拿出,但每次拿的粒数要相同,最后正好拿完.共有几种拿法?
注意：回答问题时请把每一步都列清楚.

Answer 1

(0.1+0.12+0.123+0.1234)*(0.12+0.123+0.1234+0.12345)—(0.1+0.12+0.123+01234+0.12345)*(0.12+0.123+0.1234)=(0.1+0.12+0.123+0.1234)*(0.12+0.123+0.1234+0.12345)+(0.1+0.12+0.123+0.1234)*0.1-(0.1+0.12+0.123+0.1234)*0.1—(0.1+0.12+0.123+01234+0.12345)*(0.12+0.123+0.1234)=(0.1+0.12+0.123+0.1234)*(0.1+0.12+0.123+0.1234+0.12345)—(0.1+0.12+0.123+01234+0.12345)*(0.12+0.123+0.1234)-(0.1+0.12+0.123+0.1234)*0.1=0.1*(0.1+0.12+0.123+0.1234+0.12345)—0.1*(0.1+0.12+0.123+0.1234)=0.1*0.12345=0.012345