下表列出了所有Tcl語言支持的算術運算符。假設變量A=10，變量B=20，則：

運算符	描述	例子
+	兩個數相加	A + B = 30
-	第一個操作數減去第二個操作數	A - B = -10
*	兩個操作數相乘	A * B = 200
/	分子(B)除以分母(A)	B / A = 2
%	模運算和整數除法後的餘數	B % A = 0

例子

試試下麵的例子就明白了所有Tcl語言中可用的算術運算符：

#!/usr/bin/tclsh

set a 21
set b 10
set c [expr $a + $b]
puts "Line 1 - Value of c is $c\n"
set c [expr $a - $b]
puts "Line 2 - Value of c is $c\n"
set c [expr $a * $b]
puts "Line 3 - Value of c is $c\n"
set c [expr $a / $b]
puts "Line 4 - Value of c is $c\n"
set c [expr $a % $b]
puts "Line 5 - Value of c is $c\n"

當編譯和執行上麵的程序，它會產生以下結果：

Line 1 - Value of c is 31

Line 2 - Value of c is 11

Line 3 - Value of c is 210

Line 4 - Value of c is 2

Line 5 - Value of c is 1