Unusual technology of the solution of the problems in Mathcad is showed in fig. 123 – the combination of the operators «←» (assignment of a values to a local variable), Add Line (to add the line in the program, or rather to unite the operators in the operational block) and «→» (output of symbol (analytical) value). The solution of such problem is showed in fig. 123: «If gold costs 320 dollars for ounce then how many atoms can we buy for one dollar?» The main point of the Tip is that that we can introduce into calculation the variable (the variables – in our case it is $, but how we can introduce into calculation the variable with such name we shall tell in the tip 14), which does not have any numerical value (in our case it is $). Nevertheless the problem is solved. But if the operators are separated and we change the operator «←» to «=», then the «indefinite» variable $ will brake all calculation.