1. OA.8 Determine the unknown whole number in an addition or subtraction equation relating to three whole numbersStrategies and VocabularyI made this anchor chart to summarize - modeling problem-solving with different strategies from Eureka Module 2 or ZEAR Mission 2. (CCSS)The charts can be used to teach in a small group intervention or just to see which strategies students needed to master in the previous or next grade.