This set of mental math resources includes posters and practice problems for students. These particular strategies will help your students break apart addition and subtraction problems into parts that are easier to add and subtract mentally. The mental math strategies include:
1. add ten and subtract the extra ones
2. subtract ten and add the extra ones
3. subtract the tens
4. add the tens
This set of resources directly connects to the grade 2 Common Core Standard 2.OA.B.2 (Fluently add and subtract within 20 using mental strategies).