Your views are a disgrace. Hasn't anyone ever told you that models are the place to handle database queries? Are you actually passing in multiple instance variables? Have you even heard of a presenter? My God. Alright. Don't panic. Here's what you do.
app/views/orders/index.html.erb
<h1>Orders</h1>
<div class="filters">
<%= link_to "All: #{@all_orders.count}", admin_orders_path %>