Howden (1989) described number sense as “a good intuition about numbers and their relationships. It develops gradually as a result of exploring numbers, visualizing them in a variety of contexts, and relating them in ways that are not limited by traditional algorithms” (p.11).
Howden, H. (1989). Teaching Number Sense. Arithmetic Teacher, 36(6), 6-11.
Tondevold, C. (2023). Build Math Minds. https://buildmathminds.com