How display Top 5 results from multiple table?

Question

Hi friends i have a three Tables each column data types are declared as Varchar...
I want to display the top five Total values from these tables in single column By using sql joins...i am new to sql server can anyone help me out...

Here is my sample table....
 table1

Name	Group	Total
aaa	Biologymaths	1100
bbb	Biologymaths	1150
ccc	Biologymaths	1089

Table2

Name	Group	Total
ddd	ComputerBiology	1010
eee	ComputerBiology	1101
fff	ComputerBiology	1128

Table3

Name	Group	Total
ggg	Arts	1078
hhh	Arts	1100
iii	Arts	1059