Andrei K.'s Resources


Summary: Alas, to get that perfect score, you have to reconsider everything you have been taught at school.   My system of preparation for the standardized tests in mathematics (ACT, SAT, SAT2, GRE, etc.) is somewhat unique and unconventional. In fact, it goes against the grain of most of what you have been taught in school... and likely even in a test-prep class, if you have... read more


For these sorts of questions, I prefer using no algebra.  First, let me turn Mark into Abby, by giving him 21 more pebbles: now, we have 2 Abbies and James, collecting a total of 294 + 21 = 300 + 15 = 315 pebbles.  Next, each Abby can be turned into 3 James, so that it is now 7...


Summary:  Mental math teaches students to see short, efficient solutions—rather than to blindly follow the brute-force, cookie-cutter, one-size-fit-all, show-all-your-work procedures taught at school.   To my youngest students, I lie—by omission—that vertical arithmetic does not exist.  I can usually get away with it for about a year. Until the school shows them the light... read more