My duaghter's best friend and my "adopted" daughter, to earn extra bucks runs a Mathnasium. It's a tutoring center K-12. They have to use worksheets which are CORE curriculum approved but their company publishes themselves. She often runs across these innane worksheets but understands the lingo used that's foreign to most of us. Some of it is reasonable, however, adds steps to solving problems which end up confusing many students. For instance, the one worksheet that has been going around asks kids to group a triple digit number into 100s, 10s ones. For the tactile learner this is great. Because they look at number 312 and only understand it in abstraction. Some kids can hang out in the abstraction, and understand doing stuff with 312 (adding, subtracting, multiplying). But eventually the tactile learner will have problems unless they have already learned to "see" the number 312 broken down and others, and so on. Her complaint with many of these worksheets is not the number line and the many ways of using it, but when the problem to solve is set up-a hypothetical student has used the system incorrectly-now find the mistake. She says it is often confusing to students and actually works against their ability to learn several methods of solving problems. At that young age, they often begin to confuse a "mistake" hypothetically given with the correct way to do it. The workbooks they use for tutoring does not add these clever twists but are forthright. They have found an angle to make much more money with high schoolers because certain classes have been left out altogether-geometry is now integrated and so most high schoolers are now not really learning geometry like we used to until they get to college. They are making good money teaching geometry to HSers preparing them for AP tests for college. So there is always a private angle if parents can afford it.