I worked in curriculum development for Algebra. There is a big problem we have with high school Algebra, when students ask us "what do we need this for?" there is no honest answer. The math in everyday life pages are really bogus. We are lying to these kids. Any math teacher (or parent) will confirm that this is true.
A sixth grader will know enough math to find an in-between number or hang a picture (what is called "geometry" in high school has to do with proofs and bisecting angles and has nothing to do with hanging pictures).
Let me give you an example.
In high school (assuming you had a normal high school algebra experience) you spent weeks learning how to find the roots of a polynomial. Let me ask you; could you find the roots of a polynomial now? Have you ever needed to find the roots of a polynomial? Do you know anyone who has been hurt by their inability to find the roots of a polynomial?
This is true of almost anything you learned in high school math. Most Americans never need it.
The math that you talk about... finding missing numbers and hanging pictures... and the math that the vast majority of us will ever need is all math that kids learn by the sixth grade.