New World of Education!
Surprisingly powerful Learning and Teaching machine! Our main concerns are Speed and Accuracy, not difficulty. Feel free to use a calculator. But, it might be slower. Whole family members can compete one another. Competition is the best method for EDUCATION, in any classroom, at home, or in any group. Remember why 'Wheel of Fortune' and 'Jeopardy' games are so popular(#1) for decades in USA. The most important thing is that you must enjoy. Just try once, you'll be addicted.