Abacus Lesson vs Unit Sharp

An abacus is named "Soroban" in Japan. Do you know what an abacus is? The abacus is very simple calculator used in China, Japan, Korea and so on. Some people may say "Isn't it an unnecessary tool if you have a calculator such as a smartphone?". Answer would be "No". The biggest difference between electric calculators and the abacus is whether you need to hold it in your hand when calculating. Because of its simplicity, you will be able to easily use the abacus in your mind. In the app, we will explain simple and fast method of the multiplication using the abacus. To learn multiplication, it is essential to be able to add with an abacus. If you are new to addition and subtraction, we recommend that You first learn with the following app. https://apps.apple.com/us/app/abacus-lesson-add-sub/id1526785916 This app will give you the skill of calculation of multiplication.

Unit Sharp is a mental math trainer designed to build intuition for unit conversions. Instead of relying on formulas or calculators, you learn to estimate values using scale, context, and real-world reasoning. This is not a converter — it’s a skill. --- HOW IT WORKS • Estimate the answer to a conversion problem • Enter your guess using a simple keypad • Get instant feedback based on accuracy • Improve your intuition over time --- ACCURACY-BASED SCORING Answers are graded by how close you are: • Exact • Close • Ballpark Different categories have different precision standards. Scientific units require tighter accuracy, while others allow broader estimates. Your session score reflects your average performance — consistency matters more than perfection. --- GAME MODES • Practice Mode Unlimited questions for focused training • Timed Mode Answer as many as possible under pressure --- CUSTOM TRAINING • Select specific unit categories • Drill individual conversion pairs • Build intuition where it matters most --- WHY IT WORKS Real-world thinking rarely requires exact answers. It requires fast, reasonable estimates. Unit Sharp helps you: • Think in magnitudes • Catch unrealistic numbers • Build confidence with units --- FREE FOREVER • No ads • No subscriptions • No tracking Built as a simple, useful tool for anyone who wants to think better with numbers.