Math Expression Evaluator is a library for evaluating simple mathematical expressions. It supports simple expressions such as 2.5+5.9, 17.89-2.47+7.16, 5/2/2+1.5*3+4.58, expressions with parentheses (((9-6/2)*2-4)/2-6-1)/(2+24/(2+4)), (+2.71*-1) * -34.1, 148.8898+(4e10-3), signed and exponential operands, expressions with variables:

var a = 6;
var b = 4.32m;
var c = 24.15m;
Assert.That(engine.Evaluate("(((9-a/2)*2-b)/2-a-1)/(2+c/(2+4))",new { a, b, c}), 
            Is.EqualTo((((9 - a / 2) * 2 - b) / 2 - a - 1) / (2 + c / (2 + 4))));

It is also possible to specify variables by using named arguments like this:

dynamic dynamicEngine = new ExpressionEvaluator();

var a = 6;
var b = 4.5m;
var c = 2.6m;
Assert.That(dynamicEngine.Evaluate("(c+b)*a", a: 6, b: 4.5, c: 2.6),
            Is.EqualTo((c + b) * a));