Learn how to use column addition to add 3-digit and 2-digit numbers with this Year 4 Bitesize learning guide for KS2.

Slide 1 of 4, , Start from the ones column: 3 + 9 = 12. This needs regrouping, so 12 can be regrouped to 10 + 2. Write a 2 in the ones column and write a 10 in the tens column as a 1 below the column.

Karen C. Fuson, Youngshim Kwon, Korean Children's Single-Digit Addition and Subtraction: Numbers Structured by Ten, Journal for Research in Mathematics Education, Vol. 23, No. 2 (Mar., 1992), pp.