If you're not good at mental addition, check into this problem set and become a master before you "discharge"! Each page includes an inspiring slogan! Current exams only feature problems with aligned digits, so working through this problem set will help you focus. This is the best material for those who: * Lose track of what they're calculating. * Often skip or omit numbers. * Enter the same number twice. * Subtract in the tens place but add in the ones place (or vice versa). * Always make mistakes when adding (or subtracting) certain numbers. * Often misread numbers (e.g., confusing 69 and 96, or 704 and 740). In particular, many people struggle with borrowing from 100, 500, 1,000, 5,000, or 10,000. I recommend copying the problems without writing on them, and practicing repeatedly until you've completely memorized them. B5 size (with answer key) Abacus materials are not subject to price reductions. However, if you purchase multiple items and save on shipping, the price may be reduced accordingly. Due to copyright issues, materials will not be sold below the list price. Multiple purchases are welcome! You might save on shipping. #soronyan abacus materials ← You can see all the abacus materials here. Shipping via anonymous "Nekopos" service. Please read the profile carefully! Please read! Please read! If you have no questions or need to combine items, please purchase without commenting. Soroban (abacus) Textbook Weakness Overcoming Special training Mental addition Mitrizan (mental addition) Elderly Brain training Right brain Right brain activation Right brain activation Dementia prevention