公式如下：
=RANDBETWEEN(1,100)&LOOKUP(RANDBETWEEN(1,4),{1,"+";2,"-";3,"*";4,"/"})&RANDBETWEEN(1,100)&LOOKUP(RANDBETWEEN(1,4),{1,"+";2,"-";3,"*";4,"/"})&RANDBETWEEN(1,100)&"="
结果见图：
得数是100以内还是加减乘除数是100以内？
