GoblinsCreate Account
Standards/Math/Massachusetts/2.OA.B

2.OA.B

2.OA Operations and Algebraic Thinking
2.OA.A
2.OA.B
2.OA.B.2
2.OA.C

Add and subtract within 20.

2.OA.B.2Fluently add and subtract within 20 using mental strategies. By end of grade 2, know from memory all sums of two single-digit numbers and related differences. For example, the sum 6 + 5 = 11 has related differences of 11 – 5 = 6 and 11 – 6 = 5.
Goblins

1-on-1 AI tutoring aligned to 2.OA.B. Instant help for students, real-time insights for teachers.

Used in classrooms by 100,000+ students at Baltimore County, Plano ISD, Deer Valley USD, KIPP, and districts nationwide.

Free for teachers, forever →

Resources

Privacy PolicyTerms of ServiceCareersTeacher LoginStudent Login

Communities

Access 4 Learning Community, Student Data Privacy Consortium
Goblins

© 2023-2026 Aha Moments, Inc.