South Dakota Standards
SD.4.N. Number Sense: Students will develop and use number sense to investigate the characteristics of numbers in a variety of forms and modes of operation.
4.N.3. Develop conjectures, predictions, or estimations in the process of problem solving and verify or justify the results.
4.N.3.1. Application: Students are able to estimate sums and differences in whole numbers and money to determine if a given answer is reasonable.