• # Elementary Mathematics Grade 1 Unit 2

Subject: Mathematics
Timeline: 10 days
Unit 2 Title: Place Value

Unit Overview:

This unit will give students the opportunity to build and understand how numbers are made.  The language used for this unit will be very important.  The language will support the students’ understanding of place value by using the terms, ones (cubes), tens (longs) and hundreds (flat).  Activities done in this unit will build number sense, insure the understanding of the order of counting and focus on the idea that a bundle of ten is called a “ten” (unitizing).  Students need to realize that a number can be represented in multiple ways.  For example:  24 can be 2 tens and 4 ones, 1 ten and 14 ones or 24 tens.

Unit Objectives:

At the end of this unit, all students must understand that the two digits of a two-digit number represents tens and ones and they must be able to identify the tens and ones place in a number up to 120.  They must be able to read, write and represent numbers up to 120 with base-10 blocks.  Finally, they must be able to compare two two-digit numbers using the <, >, and = symbols.

Focus Standards:

PA.CCSS.Math.Content.CC.2.1.1.B.1 Extend the counting sequence to read and write numerals to represent objects. (1.NBT.1)
PA.CCSS.Math.Content.CC.2.1.1.B.2 Use place value concepts to represent amounts of tens and ones and to compare two digit numbers. (1.NBT.2, 1.NBT.3)
PA.CCSS.Math.Content.CC.2.2.1.A.1  Represent and solve problems involving addition and subtraction within 20. (1.OA.5)

Mathematical Practice Standards:

#1 Make sense of problems and persevere in solving them.

Mathematically proficient students start by explaining to themselves the meaning of a problem and look for an entry point to its solution.  They then plan a solution pathway rather than jumping into a solution attempt.  They monitor and evaluate their progress and change course, if needed.  Students might rely on using concrete objects or pictures to help conceptualize and solve a problem.  They then check their answers to problems using a different method, and continually ask themselves, “Does this make sense?”  These students can also understand the approaches of others to solving complex problems and identify correspondences between different approaches.

#4 Model with mathematics.

Mathematically proficient students can apply the mathematics they know to solve problems arising in everyday life, society, and the workplace. In early grades, this might be as simple as writing an addition equation to describe a situation.  Mathematically proficient students who can apply what they know are comfortable making assumptions and approximations to simplify a complicated situation, realizing that these may need revision later. They are able to identify important quantities in a practical situation and map their relationships using such tools as diagrams, two-way tables, graphs, flowcharts and formulas. They can analyze those relationships mathematically to draw conclusions. They routinely interpret their mathematical results in the context of the situation and reflect on whether the results make sense, possibly improving the model if it has not served its purpose.

#5 Use appropriate tools strategically.

Mathematically proficient students consider the available tools when solving a mathematical problem. These tools might include pencil and paper, concrete models, a ruler, a protractor, or a calculator. Proficient students are sufficiently familiar with tools appropriate for their grade to make sound decisions about when each of these tools might be helpful, recognizing both the insight to be gained and their limitations.

#6 Attend to Precision.

Mathematically proficient students try to communicate precisely to others.  They use clear definitions in discussions with others and in their own reasoning.  They state the meaning of the symbols they choose, including the equals sign, consistently and appropriately.  They calculate accurately and efficiently and give carefully formulated explanations to each other.

Concepts - Students will know:
• How to build numbers
• How to break apart numbers
• Numbers can be represented in many different ways
Competencies -Students will be able to:
• Use base 10 blocks to build numbers
• Break apart numbers in tens and ones
• Represent numbers with base-10 blocks

Assessments:
• Unit 2 Progress Check
• Daily RSA

Elements of Instruction:

Kindergarten classrooms working with the Common Core State Standards for Counting and Cardinality, students master the understanding of numbers to 20.  They can count, read, and write numbers from 0 to 20.  They can compare numbers between 1 and 10 and can count objects and understand that the last number name tells the number objects counted.  Students entering first grade should also be fluent in counting forward from a given number other than 1.  After this unit, students should be able to break apart numbers into their values.

Differentiation:

Each lesson has differentiation options for each portion of the lesson.  Additional differentiation options are listed with directions and student masters in the Teacher’s Guide to Games.

Interdisciplinary Connections:
• Morning message and Math message routines.