gistfile1.txt

var sequence = new[] { 5, 4, 3, 2, 1 };

var varSum = sequence.Aggregate((sum, number) => sum + number);
var varCount = sequence.Aggregate(0, (count, number) => count + 1);
var varMin = sequence.Aggregate((min, number) => number < min ? number : min);
var varMax = sequence.Aggregate((max, number) => number > max ? number : max);
var varAverage = varSum / varCount;
var varAverageAlt = sequence.Aggregate(new { sum = 0, count = 0 },
    (anonObj, number) => new { sum = anonObj.sum + number, count = anonObj.count + 1 },
    anonObj => anonObj.sum / anonObj.count);

// use the tailored methods in production code.
//var sum = sequence.Sum();
//var count = sequence.Count();
//var min = sequence.Min();
//var max = sequence.Max();
//var average = sequence.Average();