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

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

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

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 ...

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 ...