Nasadasi: AMC 8

What is it?

American Mathematical Contest is a middle school math contest conducted by Mathematical Association of America (MAA)
Anyone Grade 8 or lower can participate
First of the AMC tests - Others being AMC 10 (covers first 2 years of high school) and AMC 12(covers all 4 years of high school except calculus)
Around 200,000 kids write the exam (~2016 stats)

Questions 1-10 are considered easy - If you can't solve these, seek help for school math. It is extremely unlikely you will do well in high school.
Questions 11-20 are considered moderately difficult. If you can solve these, you can consider yourself average in math.
Questions 21-25 are considered difficult. If you can solve these, then you are proficient in Math

Most of the math problems in many textbooks are close to being useless. You cannot learn useful math. Solving them is tantamount to copying a large book by hand with the objective of learning literature.
An objective assessment of your math skills. Math contests in the erstwhile USSR and most of Asia is for mathematically talented kids. The beginning level of the problems is pretty high. Not being able to solve them doesn't necessarily mean you lack math skills. But Math contests in North America is for the masses. There will be problems that students every level can solve. Doing well in these mean you are good at math and not being able to do any or only able to do 1 or 2 problems mean that you are bad at math even at a basic level. You need help at school if you perform at the bottom. So contests like AMC 8 and CEMC are good diagnostic tools.
Opportunity to practice problem solving. There is no material advantage of writing AMC 8 (unlike AMC 10 and 12). You don't get special admission or recognition anywhere based on your AMC 8. The reward is itself.
How contest writing helps

Take Old Practice Exams in a simulated test environment
Keep a record of every practice test - marking 1 for correct, 1! for correct guess, 0 for wrong, 0! for incorrect guesses, 0? for attempted (but no answer) and blank for skipped
Questions 1-10 are all about using tricks for school math. If you don't use the tricks or shortcuts you may still solve it but will spend time that you can't use for other problems.
In geometry problems draw additional lines or grids to see if the problem gets simplified
Learn the basics - divisibility tests,

Have a test kit ready - Pencil, Paper, Graph paper, rulers, protractors, erasers
Organize your scratch paper so you can check your work faster

Divide paper to grid
Box answer, draw clear diagram.
Put a circle on unsure answers (put on problem numbers)
No eraser on scratch paper
Even write down mental math answers (don't skip writing down answers)
Don't solve more than what is required.
Even if guessing answers write choices down e.g A or B (dont forget to circle the question)

A great tactic to start most geometry problems is to just figure out all information you can to get started and then mark them on the diagram.
If something is too complex try to break it up into smaller pieces that are easier to handle
Dont panic if you don't understand a problem. Take a deep breath!!
When computing areas of complex/irregular figures try to start computing areas of simple figures (triangles, rectangles, circles) and then adding or subtracting the smaller areas to get the area of the complex figure.
In counting problems, check for boundary items. It is easy to make one-off errors and undercount or overcount.
It is important to be systematic when solving a counting problem. When it's easy to get lost, it's even more important.
In counting problems, it can be helpful to come up with a different way of getting the answer, so you can check if your answer is correct.