This application is a simple Japanese abacus (soroban / そろばん). It has a free mode where you can use the abacus freely, and a challenge mode with 4 operations (addition, subtraction, one and two digit multiplication, and division) and 3 difficulty levels (easy, medium, hard) where you must race against the clock to perform calculations. Contains tutorials for: * basic concepts * addition * subtraction * one-digit multiplication * two-digit multiplication NOTE: no tutorial available yet for division, but that's coming soon. (This is just a hobby project I'm doing for fun. This app is free and doesn't have in-app purchases or ads). 這個應用程序是一個簡單的日本算盤（soroban /そろばん）。它有一個免費的模式，您可以自由使用算盤，以及挑戰(zhàn)模式與4的操作（加法，減法，一和二位數(shù)的乘法和除法）和3個難度級別（易，中，硬），你必須爭分奪秒時鐘來執(zhí)行計算。 包含教程： *基本概念 *此外 *減法 * 1位數(shù)乘法 *兩位數(shù)乘法 注：沒有可用的教程卻為師，但是這即將到來。 （這只是一個愛好項目我做的樂趣。這個應用程序是免費的，沒有在應用程序內(nèi)購買或廣告）。