Differences between "on"and "about "
A book on maths
A book about maths
Are there any differences

Question

Differences  between "on"and "about "
A book on maths 
A book about maths 
Are there any differences

Answer

on 是 在上面 在边上 在星期几   在左边  在右边   about  关于  大约

Answer

Both are propositions 
on......>means above or in the top of 
for example:
my book is on the table"the book is above or in the top of  the table
whereas 
about..........> around 
for example ......>I spend monthly about 1000$
hope that helps