<p>Generally speaking, only the most selective colleges & universities require the SAT Subject tests, and they usually require two, although a few require three Subject tests. For the vast majority of colleges & universities, they will accept the ACT and the SAT interchangeably, usually specifying that the ACT should include writing.</p>
<p>You are correct, the SAT “Reasoning” test does not have a science section – it is made up of three components, Critical Reading, Math and Writing.</p>
<p>There are “concordance” tables which many colleges use to convert ACT scores to SAT scores, and vice versa.</p>
<p>Some kids do better on the ACT, some better on the SAT. My 2 older kids did about the same. The consensus is that the ACT is a little more fact based, based on material kids learn, or should learn, in high school. The SAT has its origins in Army “intelligence” tests. For many years the “A” in SAT stood for Aptitude. College Board has since dropped that nomenclature, but there is still something of a different flavor to the two exams.</p>
<p>It is probably worth while taking a practice test of both types (SAT vs. ACT) to see if your kid does significantly better, in percentile terms, on one versus the other. If that is the case, then I think it is worth it to take both tests for real.</p>