南外英语数学题Do you know the different between number and digit?do you know the different between number and digit?Nancy has a book.Now she wants to number the pages with 813 digits.How many pages does the book have?大家答的都很好,baby

南外英语数学题Do you know the different between number and digit?
do you know the different between number and digit?Nancy has a book.Now she wants to number the pages with 813 digits.How many pages does the book have?
大家答的都很好,babybluein答得更详细些,所以最佳就给他啦,

number表示一个数,digit表示一个数字
如：18是一个number,有2个digits
而题目说Nancy有本书,每页的页码的数中的数字个数加起来是813,问这本书有多少页?
首先,1到9有9个数字.
接下来就是两位数,10-99有90*2=180个数字.
而书里有813个数字,所以还余下813-9-180=624个数字.
接下来编码的页码都是三位数,624可以编624/3=208个页码.
所以这本书有100+208-1=307页.