If you're not good at mental addition, check into this problem set and become a master before you leave! Each page includes an inspiring slogan! Current exams only feature problems with aligned digits, so working through this problem set will help you concentrate. If you find yourself losing track of what you're calculating, If you often skip numbers (forget to include them), If you always make mistakes when adding (or subtracting) certain numbers, if you often misread numbers (mistaking 69 for 96, or entering 740 instead of 704), If you subtract in the tens place but add in the ones place, Many people struggle with borrowing from 10,000 or 5,000. This is the best material for those people. I recommend copying the problems without writing on them, and practicing them repeatedly until you completely memorize them. B5 size (with answer key) If you only purchase this item, it will be sent in simple packaging (waterproof only) via non-standard mail. Regular mail is cheap, but if your mailbox is small, it may be folded to fit. If your mailbox can't accommodate B5 size, or if you need anonymous shipping, you can upgrade to Nekopos for an additional 30 yen, so please comment. Discounts on abacus materials are ❌. If you purchase multiple items and save on shipping, the price will be reduced accordingly, so please comment. #soronyan abacus materials ← You can see all the abacus materials here. Please read the profile carefully❗️carefully❗️carefully❗️ before purchasing without comments if you have no questions or need to combine orders. Weakness Overcome Abacus materials Mental addition Mitorizan (mental addition) Mental addition Elderly Brain training Right brain Right brain activation Preventing aging