Description D-Level Learning Objectives Building on the addition skills up to +4 mastered in Level C, this level focuses on addition from +5 to +10 and addition with larger numbers, helping children develop the essential mental arithmetic skills needed for calculation. Book (Volume/Month) - Week (Session) - Learning Content D1 Book, Weeks 1-4: Addition +5: (1~9)+5, (1~14)+5, (1~19)+5 Addition +6: (1~9)+6, (1~13)+6, (1~19)+6 Achievement Test D2 Book, Weeks 1-4: Addition +7: (1~9)+7, (1~19)+7, (1~23)+7 Addition +8: (1~9)+8, (1~19)+8, (1~22)+8 Achievement Test D3 Book, Weeks 1-4: Addition +9: (1~9)+9, (1~15)+9, (1~21)+9 Addition +10: (1~9)+10, (1~15)+10, (1~20)+10 Achievement Test D4 Book, Weeks 1-4: Comprehensive Addition +5 to +10: Numbers up to 19 + (5~6), Numbers up to 19 + (7~8) Numbers up to 19 + (9~10), Numbers up to 19 + (5~10) Addition with Larger Numbers Achievement Test D5 Book, Weeks 1-4: Addition with Larger Numbers: Sums up to 15, Sums up to 20, Sums up to 25 Sums up to 30, Sums up to 35, Sums up to 40 Comprehensive Addition Review (Level D) Final Test