Bar Models
Article from the NCETM about bar models-
https://www.ncetm.org.uk/classroom-resources/ca-the-bar-model/
Maths No Problem articles on bar models-
https://mathsnoproblem.com/en/approach/bar-modelling/
Oak Academy lessons on the bar model method-
https://classroom.thenational.academy/units/addition-and-subtraction-word-problems-cefb