This app offers timed training for mental arithmetic and estimation skills. It includes various arithmetic operations, comparison challenges, and graded sessions to improve your calculation speed and accuracy. Unlock full features with a premium subscription.
4.0.0
October 9, 2026
What's new in 4.0.0 • Home tab: your streak, Today's Round, and Today's Picks on one screen. • Pizzle League: tap "See my rank" after an exam-mode round to see this week's ranking in Pizzle. • My grades: see your latest grade for each exam mode in My Page. • Exam mode is now always 20 questions. • Refined the difficulty and question mix of Comparison drills. • Fixed 3-digit ÷ 1-digit division often showing 100 ÷ 1. • Subscriptions: offer terms and Restore Purchases on the paywall, Manage Subscription in My Page. • VoiceOver now reads calculator keys and fractions. • Added Lee Jieun's Beopgalpi to recommended apps.
MoreOttugi is a timed trainer designed to enhance mental arithmetic and estimation skills. It offers various modes like Arithmetic, Comparison, and Graded sessions to challenge users.
Ottugi supports practicing arithmetic with numbers ranging from 1-digit to 4-digit. You can choose specific operations or use the Exam Mode which mixes addition, subtraction, multiplication, and division randomly.
In Comparison mode, you don't need exact answers. You quickly decide which side of a comparison is larger. It includes 7 types of comparisons like fractions, products, and growth rates.
Yes, every session in Ottugi is graded from S to D based on your seconds per question. Wrong answers incur a time penalty, discouraging rapid guessing.
Yes, Ottugi is supported on both iPhone and iPad devices, offering a consistent experience across Apple's mobile platforms.
The premium subscription is an auto-renewing service that unlocks full training for the Comparison and Past Exam modes. The base Arithmetic training is entirely free.
The latest version of Ottugi was released on October 9, 2026, indicating active development and updates. The app was initially released on September 19, 2025.
Ottugi supports both English and Korean languages, making it accessible to a wider range of users. It also features both light and dark mode options.
Train calc and focus every day
