Summary table using Coffeescript? - coffeescript

Question

I've programmed a summary chart, and I'm trying to add a "Totals" line that will sum up three columns. The exercise is comprised of a number of questions, and the participant can increase, decrease or maintain a certain dollar amount. The column B total shows the initial values (where the slider starts off on). The column C shows the amount the participant either increased or decreased and the last column shows the resulting dollar amount. (B + C)
Here's an example of the summary chart
Column A --- B ------ C------ D
Question 1 | 100$ | +28$ | 128$ |
Question 2 | 150$ | (10$) | 140$ |
Totals ------| 250$ | +18$ | 268$ |
So far I've been able to program the totals for column B and D, but I can't figure out how to show a total for column C.
class window.CustomSimulator extends window.TaxSimulator
constructor: (#options = {}) ->
super
#updateTable()
update: ->
super
#updateTable()
updateTable: ->
self = this
$table = $('<table class="table table-condensed"><thead><tr><th>Category</th><th>Before</th><th>Your Choice</th><th>After</th></tr></table>')
$tbody = $('<tbody></tbody>')
before_total = 0
after_total = 0
#scope.find('.slider').each ->
$this = $(this)
$parents = $this.parents('tr')
category = $parents.find('.header').clone().children().remove().end().text().replace(/How would you adjust service levels and property tax funding for /, '').replace('?', '')
before = self.tipScaler($this, $this.data('initial'))
your_choice = $parents.find('.value').text()
after = $parents.find('.tip-content').text()
if $parents.find('.key').text() == 'Decrease:'
css_class = 'decrease'
your_choice = "(#{your_choice})"
else
css_class = 'increase'
$tr = $("""<tr><td>#{category}</td><td>#{before}</td><td class="table-#{css_class}">#{your_choice}</td><td>#{after}</td></tr>""")
$tbody.append($tr)
before_total += parseFloat(before.replace('$', ''))
after_total += parseFloat(after.replace('$', ''))
before_total = SimulatorHelper.number_to_currency(before_total, precision: 2, strip_insignificant_zeros: true)
after_total = SimulatorHelper.number_to_currency(after_total, precision: 2, strip_insignificant_zeros: true)
$("""<tfoot><tr><th>Totals</th><th>#{before_total}</th></th><th><th>#{after_total}</th></tr></tfoot>""").appendTo($table)
$table.append($tbody)
$('#summary-table').html($table)
I'm pretty new at this so I'm not sure if this is enough information.
Thanks!