Operating in Russia and some other countries, standards for design calculations, which are shared by the teachers of technical colleges, require that, prior to the conclusion of the numerical response was duplicated formula where the variables involved in the calculation, this would be their numerical values. To meet this requirement, the program was introduced Mathcad operator explicit. But Mathcad users a lot of criticism for that operator. First, it displays the values of the variables involved in the calculation with the source units and you can not change to other, more suitable for the user. Thus, in our calculation of the radius of the cylinder is given in millimeters, and the height - in inches. These units were duplicated in the formula for the volume of the cylinder with the substituted values of variables. Secondly, you can not change the number of separately decimals in individual numerical values substituted for the variables. Third, according to the standards necessary to remove all the units in the values of these variables. These customer feedback scientific calculator Mathcad recorded in the lower three terms in the figure. You can, of course, to convince the developer package Mathcad make future versions of these changes. But you can do to change standards for design of settlement documents and regard of the new (computer) calculation methods. The fact that these standards were developed back in the pre-computer era, and consider the following technology calculations. Expert in a particular field of science and technology, designing an object and making calculations with a slide rule, calculator or adding machine, was to duplicate the formula with the substitution of the numerical values of the variables to somebody else could verify the arithmetic calculations. In large project organizations are departments where special people (original arithmetic correctors) performed these checks and identify possible arithmetic errors such as 2 + 2 = 5. The computer to perform such a test, of course, makes no sense. Consequently, there is no point in duplicating the formula with the substitution of the numerical values of variables. However, outdated standards require it. Check in modern computer calculations to another - whether those variables appear in formulas, which they have a numeric value and whether the formula itself.