This document provides an outline for a lesson plan on representing and adding 2-digit numbers. The lesson will have students: 1) Explore place value through manipulating place value cards and building 2-digit numbers. 2) Play a game taking turns describing 2-digit numbers in expanded form for their partner to write down. 3) Add the two numbers together using expanded notation and explain their strategies. The lesson aims to develop students' understanding of place value and addition of 2-digit numbers through concrete and pictorial representations.