Teaching Addition and Subtraction Within Ten Using CCSS K.OA.2
NOTE: This document is a separate set of problems and is designed as a companion to the Teaching Addition and Subtraction Within Five Using CCSS K.OA.2 document. The 21 problems in the “within five” document are not included in this document. This document is the 43 problems that are within 10, but not within 5.
Young children benefit from a strategy from Singapore Math—namely using a Concrete to Pictorial to Abstract (CPA) strategy.
Each concept is introduced at the concrete level using a word problem that is solved using manipulatives on a special mat showing a ten frame (or two ten-frames for some types of problems).
After the concept is introduced with concrete manipulatives on a ten frame, additional word problems are shown using a pictorial approach with pictures of the ten frame so that drawings can be made to represent the problem and its solution.
The final step is the abstract version where the word problem is written in algorithmic form and solved writing the number sentence and its solution.
The unit contains a 21-page teacher’s guide and 30 pages of word problems involving all 43 basic addition facts and basic subtraction facts utilized repeatedly in the concrete, pictorial, & abstract models of addition, take-away subtraction, comparative subtraction, missing addend—part/part/whole subtraction, and missing addend—completion subtraction.
Students who complete this unit will have a very sophisticated understanding of both addition and subtraction!