Description Level E Learning Objectives Building on the basic mental arithmetic skills developed in Level D, this level focuses on learning basic subtraction up to minus 10, and aims to complete mental arithmetic ability through continued practice of addition and subtraction. Book (Volume/Month) - Week - Learning Content E1: Weeks 1~4 Understanding subtraction (subtracting smaller numbers) Subtracting 1: (1~12)-1 Subtracting 2: (1~13)-2 Subtracting 3: (1~15)-3 Practice up to (1~15)-3 Achievement test E2: Weeks 1~4 Subtracting 4~10: (1~15)-4, (1~15)-5, (1~15)-6, (1~15)-7, (1~15)-8, (1~15)-9, (1~15)-10 Practice up to (1~15)-10 Achievement test E3: Weeks 1~4 Subtracting from numbers 11~12 Subtracting from numbers 13~14 Subtracting from numbers 15~16 Subtracting from numbers up to 16 Comprehensive achievement test E4: Weeks 1~4 Subtracting from numbers 17~19 Subtracting from numbers 20~22 Subtracting from numbers 23~25 Subtracting from numbers up to 25 Comprehensive achievement test E5: Weeks 1~4 Complete review of addition and subtraction (Levels C~E) Final test