Activity: Adding 2-digit numbers Complete this interactive activity to learn more about adding numbers using column addition and then put your knowledge to the test with a quiz.

Join Mrs. Markavich for a word problem with her friend Professor Barble! Next get ready to have some fun with Value Pak as we add 2-digit numbers using base ten strategies!

The formal school algorithms are still used for larger numbers and decimals but we encourage students to use whichever strategy they prefer for two-digit addition.

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 ...