This works if the two numbers are close together. Empty number lines can help you work out the difference between the two numbers.

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

Draw two cards from the deck and subtract the two numbers of the cards using a number line. Remember to use the biggest number first! Download this worksheet to help you with the counting back ...

Mrs. McCartney talks addition with D.C.; practices hopping the numberline with Springling.

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 ...