Arithmetic operation between Meteor Helpers - mongodb

Question

I am handling a new Meteor test project and came across a doubt.. Please try to find a solution for me.
This application has 2 'helpers' for the same template.
Template.scoreBoard.helpers({
scroeHalfTime:function(){
var cursor = return MyCollection.find({player:"selectedPlayer"}).fetch();
var sum = 0;
cursor.forEach(function(player){
sum = sum + Number(player.scoreHalf)});
return sum;
},
scroeFullTime:function(){
var cursor = return MyCollection.find({player:"selectedPlayer"}).fetch();
var sum = 0;
cursor.forEach(function(player){
sum = sum + Number(player.scoreFull)});
return sum;
}
I would like to return the difference between this 'scroeHalfTime' and 'scroeFullTime', this will give me a result of how much did the player scored before and after half time.
Following codes did not work for me..
{{ScroeFullTime - scroeHalfTime}}
{{ScroeFullTime() - scroeHalfTime()}}
{{(ScroeFullTime - scroeHalfTime)}}

Answer 1

Simply create variable which will hold both values, like
var halfTime=0, fullTime=0;
Template.scoreBoard.helpers({
scroeHalfTime:function(){
var cursor = return MyCollection.find({player:"selectedPlayer"}).fetch();
var sum = 0;
cursor.forEach(function(player){
sum = sum + Number(player.scoreHalf)});
halfTime = sum;
return sum;
},
scroeFullTime:function(){
var cursor = return MyCollection.find({player:"selectedPlayer"}).fetch();
var sum = 0;
cursor.forEach(function(player){
sum = sum + Number(player.scoreFull)});
fullTime = sum;
return sum;
},
difference: function(){
return fullTime - halfTime;
}

Answer 2

Simple call {{scoreFullTime - scoreHalf Time}}. You can do that inside the template.

Answer 3

Solved..
Created Another Helper, and now Template. scoreBoard.helpers looks like,
Template.scoreBoard.helpers({
scroeHalfTime:function(){
var cursor = return MyCollection.find({player:"selectedPlayer"}).fetch();
var sum = 0;
cursor.forEach(function(player){
sum = sum + Number(player.scoreHalf);
});
return sum;
},
scroeFullTime:function(){
var cursor = return MyCollection.find({player:"selectedPlayer"}).fetch();
var sum = 0;
cursor.forEach(function(player){
sum = sum + Number(player.scoreFull)});
return sum;
},
scoreDifference:function(fullTime,halfTime){
var halfCursor = return MyCollection.find({player:"selectedPlayer"}).fetch();
var halfScore = 0;
halfCursor.forEach(function(player){
halfScore = halfScore + Number(player.scoreHalf);
})
var fullCursor = return MyCollection.find({player:"selectedPlayer"}).fetch();
var fullScore = 0;
fullCursor.forEach(function(player){
fullScore = fullScore + Number(player.scoreFull);
})
});
return fullScore - halfScore;
}
});