


Math can be an obvious equation, be it simple or complex and many of the stamps so far shown contain such equations.
However, I believe there is also math on stamps which is hidden within a word problem. And as with some word problems one needs to eliminate what is extraneous to the actual math being called for in the word problem. My example show below has much which is extraneous and such can be repeated with many different examples of the same problem but different extraneous material.
In each case, there is a variable on the word problem stamp, a variable that represents a constant but for which the constant changes over time, representing a series of numbers while also being a momentary constant. While I am showing one such solution set, other solution sets can be determined for the issues of other countries.
First variable, which when limited to one country, is a true constant for that country remaining unchanging in its value.
The second variable, displayed in different manners depending on which First Variable is selected. There are a variety of second variables in use each with their own unique series of periodic constants. Interestingly, once used, the second variable is "locked" and the series it represents ceases to grow unlike the unused version.
Here, as shown above, the first variable = USA
The second variable is expressed in three ways:
First Class = First Class Forever = Forever = X with X being the current and historic series of the number assigned for such postage.
The design element beyond the country representation and the value variable is what makes the stamp beautiful but is superfluous to the word problem math, except when used to identify the beginning value of the series represented.