diff --git a/app/controllers/invoices_controller.rb b/app/controllers/invoices_controller.rb
index 9416980..f0df12d 100644
--- a/app/controllers/invoices_controller.rb
+++ b/app/controllers/invoices_controller.rb
@@ -1,35 +1,32 @@
 # encoding: utf-8
 class InvoicesController < ApplicationController
   def index
-    @invoices = Invoice.where(user_id: current_user.id)
+    @invoices = Invoice.where(user_id: current_user.id).order('created_at DESC')
   end
 
   def show
     @invoice = Invoice.find(params[:id])
     @vats = Vat.all
     respond_to do |format|
-      format.html {@inv_format = 'html'}
+      format.html { @inv_format = 'html' }
       format.pdf do
-        render pdf: "Faktura_VAT_#{@invoice.id}",   # Excluding ".pdf" extension.
-        disposition: 'attachment',
-        layout: 'pdf',
-        encoding: 'UTF-8',
-        page_size: 'A4',
-        margin:  {   top:               8,                     # default 10 (mm)
-                     bottom:            8,
-                     left:              8,
-                     right:             8 },
-        viewport_size: '1336x1024'
+        render pdf: "Faktura_VAT_#{@invoice.id}", # Excluding ".pdf" extension.
+               disposition: 'attachment',
+               layout: 'pdf',
+               encoding: 'UTF-8',
+               page_size: 'A4',
+               margin: { top: 8, bottom: 8, left: 8, right: 8 },
+               viewport_size: '1336x1024'
       end
     end
   end
 
   def new
     @invoice = Invoice.new(date: Date.today, date_of_payment: Date.today + 14.days)
-    inv = Invoice.where('date > ?', Date.new(Date.today.year,1,1)).last
-    if !inv.blank?
+    inv = Invoice.where('date > ?', Date.new(Date.today.year, 1, 1)).last
+    unless inv.blank?
       nr = inv.number
-      new_nr = (nr.split("/")[0].to_i + 1).to_s + "/" + nr.split("/")[1]
+      new_nr = (nr.split('/')[0].to_i + 1).to_s + '/' + nr.split('/')[1]
       @invoice.number = new_nr
     end
     @invoice.invoice_products.build
@@ -73,7 +70,11 @@ class InvoicesController < ApplicationController
   end
 
   private
+
   def invoice_params
-    params.require(:invoice).permit(:number, :user_firm_id, :customer_id, :date, :date_of_payment, invoice_products_attributes: [:id, :product_id, :qty, :netto_price, :_destroy])
+    params.require(:invoice)
+          .permit(:number, :user_firm_id, :customer_id, :date,
+                  :date_of_payment,
+                  invoice_products_attributes: [:id, :product_id, :qty, :netto_price, :_destroy])
   end
 end
diff --git a/app/models/invoice.rb b/app/models/invoice.rb
index 19670ef..8d63e5a 100644
--- a/app/models/invoice.rb
+++ b/app/models/invoice.rb
@@ -2,11 +2,11 @@ class Invoice < ApplicationRecord
   belongs_to :user
   belongs_to :user_firm
   belongs_to :customer
-  has_many :invoice_products, inverse_of: :invoice
+  has_many :invoice_products, inverse_of: :invoice, dependent: :destroy
   accepts_nested_attributes_for :invoice_products, allow_destroy: true
 
   def netto_amount
-    0.0
+    invoice_products.sum('invoice_products.netto_price * invoice_products.qty')
   end
 
   def products_with_tax(vat_id)
diff --git a/app/views/invoices/_show.html.erb b/app/views/invoices/_show.html.erb
index 249d2b7..7904a77 100644
--- a/app/views/invoices/_show.html.erb
+++ b/app/views/invoices/_show.html.erb
@@ -166,7 +166,7 @@
                 <td valign="bottom">Kwota do zapłaty: </td><td><span style="font-size:18px"><b><%= number_with_precision(total_arr[2], delimiter: " ", separator: ",", precision: 2) %> PLN</b></span></td>
               </tr>
               <tr>
-                <td>Słownie do zapłaty: </td><td><b><%= decimal_to_word(total_arr[2]) %></b></td>
+                <td>Słownie do zapłaty: </td><td><b><%= decimal_to_word(('%.2f' % total_arr[2]).to_f) %></b></td>
               </tr>
               <tr>
                 <td>Forma płatności: </td><td><b>Przelew</b></td>