COKER, DAWNE. "T4T Addition & Subtraction Strategies". OER Commons. Institute for the Study of Knowledge Management in Education, 13 Jul. 2019. Web. 28 Sep. 2023. <https://goopennc.oercommons.org/authoring/1063-t4t-addition-subtraction-strategies>.
COKER, D. (2019, July 13). T4T Addition & Subtraction Strategies. OER Commons. Retrieved September 28, 2023, from https://goopennc.oercommons.org/authoring/1063-t4t-addition-subtraction-strategies.