Introduction

This is a lesson designed to introduce the concept of part-part-whole relationships to first graders. Through several engaging activities, students will experiment with putting two groups, or “parts”, together to make a “whole”. This lesson includes a whole-group activity and a partner activity, as well as independent work and evaluation.

Learning Objectives

CCSS.MATH.CONTENT.1.OA.C.6

  • Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on.
  • Making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14)
  • Decomposing a number leading to a ten (e.g., 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9)
  • Using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 – 8 = 4)
  • Creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).

 

For the full lesson plan, download the PDF.