Edit numbers in the right column and the "total:" field will tell you their sum.

number #10
number #20
number #30
number #40
number #50
number #60
number #70
number #80
number #90
number #100
total:0

This sample demonstrates use of functions in CSSS!. Magick is done by the following rule:

   value-changed!: 
    total = 0, 
    $(td.number) -> @(el) total = total + el:value,
    $1(td#total):value = total;
  

Declare variable total with initial value 0.

Declare anonymous function @(el) with single parameter el and body of single statement:

 total = total + el:value

$(td.number) '->' function - call function on the right for each element of collection on the left that is a set of elements satisfying $(td.number).

Set text of td#total equal to the total.