As the numbers that I show are not too high, observation may not have enough value.

Typically, the math apps downloads have a proportion of users fairly well distributed among all countries. However, there is always a predominance of the US downloads:

Example graph of a usual app of active users statistics:

(humble numbers related to a calculator)

In my Google Play page, there is one of the oldest applications that I've done, devoted to linear algebra and the Gauss-Jordan elimination as a method of solving two equations with two unknowns.

For the application to be a little more attractive, I called it "Adding apples and oranges", referring to an equation are getting really different variables to give a result.

The proportion of current statistics of this application are quite different from other applications. There is a predominance of US downloads:

(humble numbers related to a Apples and oranges app)

While this difference so marked, it makes me think:

It could be that the education authorities of the US had greater knowledge of applied mathematics than education authorities of other countries?

Knowledge of the intellectual basis of the information revolution which we live has influenced the educational guidance of the US?

Or is the result of many parents with deep and old computer knowledge?

What is it that justifies this big difference?

I've searched Common Core related items with the elimination of Gauss-Jordan:

Here are some examples about the related items:

CCSS.MATH.CONTENT.8.EE.C.8 - A, B, C.

CCSS.MATH.CONTENT.HSA.REI.C.6

CCSS.MATH.CONTENT.HSA.REI.D.12

CCSS.MATH.CONTENT.HSA.REI.C.6

CCSS.MATH.CONTENT.HSA.REI.D.12

I can not draw a conclusion. Just leave the data in case anyone is able to solve these questions.