There is a not so old saying, "What gets measured gets managed." The trouble is when what is getting measured is the wrong thing then what is getting managed is getting mismanaged.
In the computer industry there was a time when KLOC was all the rage. That is a programmers productivity was measured by the thousands of lines of code he generated. Well, programmers aren't dumb, so they changed their coding style to write their code in the most expansive way possible. It didn't make the code any better nor did it make production go any faster, but they got pay raises if their code was bloated. I was once part of a team working over some code and one of the developers found 10,000 lines of code that was never called and he deleted it because it was unneeded. Why was it there? To boost the numbers when KLOC was the managed number.
I was also in a call center, and the only thing they measured was call time. CSRs might not get paid very much but they aren't dumb either. It wasn't uncommon for them to hang up if a call went too long. There was no real way to measure customer satisfaction.
When it comes to your children's education: What are you measuring?
I think it is safe to say that virtually all of us have had classes that all you needed to do was cram some facts for the test, regurgitate them and then forget them because we had no reason to help them stick.
A test is a useful tool if you have a class of 20+ children. It gives you an idea of how the class as a whole is doing. You aren't going to have that many children. You can use more useful techniques to find out how well your child is learning. The best one is to just ask them to help solve problems for you as they come up in daily life. Watching how they solve problems as they come up will tell you a lot about how they are learning.
What we have to do is to be aware of all the teaching opportunities there are all around us. Cooking is one of the great ones. Cooking involves physics, chemistry, and biology. Changing the size of the recipe is a great for practicing fractions.