<p>Some countries do not have 13 years (k -12) system. They start kids at 7 in first grade and they have only 10 grades. What you teach is more important than when you start them. You can definitely teach much more challenging material to a 7 y o, and kindergarten should not be even considered as an academic year, no academics. No reading requirements or any kind of testing is done before kids enter first grade at 7. All this testing is just waste of resources. My own D. tested very low before kindergarten and we still put her ahead, yes she went before she turned 5, The girl ended up never having a single B in her entire k thru college graduation experience and currently is one of the youngest in Med. School.<br>
In the 1 - 10 system (vs k - 12) system, they start talking about algebra concepts in first grade. Why not? They start algebra in 5th grade, chem. in 5th grade, physics in 6th grade. They gradually move to having algebra, geometry and trig all at the same time (different days of the week) and having physcis material taught at the higher level of difficulty based on the level of math learned so far. There are also separate classed for history, biology, botany, geography, not all mushed together. No wonder, that American kids have such a huge problem entering college in engineering major. It is NOT an individual kid problem kids are ALL smart, they are not stupid. American kids are not prepared at all by k -12 education. Some immigrants organize their own school to bring their kids’ level in math and science up, others (from some African countries, believe it or not) thinking about sending their kids back home to get pre-college education. American k -12 is at miserably low level, even in the best schools as all schools have about the same program. It is NOT possible to teach physics in one year, period, it is the most ridiculous assumption of them all. The best teacher is the one who recognizes that fact and teach only one part (the most difficult) - mechanics. None of it is possible without great background in math. Math is nothing more but the universal language of science. Until this is recognized, k -12 will continue to be a drag, boring and not challenging experience, that most kids feel very negative about. It does not have to be this way at all.</p>