# Clip 1/29: Standard 1: Making Sense and Perseverance Using Base Ten Part 1

## Overview

*Mathematically proficient students start by explaining to themselves the meaning of a problem and looking for entry points to its solution...They make conjectures about the form and meaning of the solution and plan a solution pathway rather than simply jumping into a solution attempt. They consider analogous problems, and try special cases and simpler forms of the original problem in order to gain insight into its solution...Younger students might rely on using concrete objects or pictures to help conceptualize and solve a problem. Mathematically proficient students check their answers to problems using a different method, and they continually ask themselves, “Does this make sense?” They can understand the approaches of others to solving complex problems.*

Liz O'Neill works with her first grade students engaging them in composing and decomposing numbers within twenty. She begins with two warm-up activities engaging students in working with numbers less than 20. Using sentence frames, students shared with their partner what number they saw and how they saw it. A variety of ways were discussed as a whole group after everyone had a chance to share with their partner. Students then played the game "How Many are Hiding?" Student pairs were given a bag with 10 cubes, a paper plate, and the "How Many Are Hiding Recording Sheet". The partner game gives students practice in composing and decomposing numbers within ten. In addition, sentence frames were posted on the board so students could produce academic language using structured student talk and convince their partners with oral justification.

**See this video in the context of an entire lesson.**

**(Parts 1 & 2)**