Calculating collection data before rendering in Meteor.js -

i'm new meteor.js , want understand basics. want calculations data in collection , render dom. should rendered dom {{#each}} loop. how can this?

the html looks similar this:

{{#each location}}    <div>{{name}}</div>    <div>{{calculated_distance}}</div> {{/each}} 

the js:

template.list.location = function (){   return collection.find({     location :        { $near :         { $geometry :           { type : "point",             coordinates : [long, lat] },                             $maxdistance: 430         }}}); } 

this allows me post data in collection. how access {{calculated_distance}} each document in collection?

if understand correctly can use helper:

template.list.helpers ({     calculated_distance: function() {         var lat = this.location.coordinates.lat;         var lng = this.location.coordinates.long;          var somecalculation = ...          return somecalculation;     } }); 

inside helper have context of this specific element in location collection (as loop through them). in helper can calculate distances need , show them in html. stands right now, html fine.