But doing twice as many problems is not the same as drilling. When people say "drilling" in American education, they generally mean doing simple and mechanical

But doing twice as many problems is not the same as drilling. When people say "drilling" in American education, they generally mean doing simple and mechanical problems for speed. For instance, the multiplication drills at some schools involve playing a voice on a CD or mp4 that speaks multiplication problems at a certain rate. Now, doing many exercises is a different thing! one that I encourage! In most textbooks, exercises range in difficulty and approach. I write math problem sets for students, and I build them to go from mechanical to sophisticated. The last few problems involve proofs, applications, links between different areas of mathematics and statistics. Students in my class who just do probability drills will not be able to do the last problem on the problem set. They don't have any practice at problem-solving in this context. Students who do all the exercises, and more, can do amazing things.