An article teaching adding and subtracting numbers with 1 or 2 digits.

Addition & subtraction strategies to solve two-digit equations using an open number line.

Researchers from 4 projects with a problem-solving approach to teaching and learning multidigit number concepts and operations describe (a) a common framework of conceptual structures children ...

A Maths guide to learning and practising dividing a 2-digit number by a 1-digit number using different methods (no remainder).