Students extend their place value knowledge to 1,000 and use this knowledge to represent and compare threedigit numbers. Students are also introduced to money, identifying coins and their value, and determining the value of coin collections.
Math
Unit 4
2nd Grade
In Unit 4, 2nd grade students build on their understanding of place value with the introduction of a new unit, a hundred. By extending their understanding that 10 ones form a ten, they learn that 10 tens form a hundred. With their knowledge of a hundred, students further their understanding of threedigit numbers by expanding their count sequence to 1,000. Their work with place value is reinforced by their work with money as they identify coins and determine the value of coin collections, as well as put this to work in context with onestep and twostep word problems.
In Topic A, students learn about a hundred and threedigit numbers (2.NBT.A.1). They use concrete base ten blocks to build threedigit numbers and understand that these numbers are made of hundreds, tens, and ones. As they build their concept of numbers with multiple hundreds they also are introduced to the idea that 10 hundreds make a thousand. That is the extent of students' understanding about a thousand as that is where their count sequence ends. Throughout the topic, students work on identifying and building threedigit numbers. They understand that threedigit numbers can be rewritten with more than 10 units of ones or tens. This work lays the foundation for adding and subtracting with rebundling. Students also learn to read and write numbers in all forms including, unit form, number form, and expanded form (2.NBT.A.3).
In Topic B, students extend their formal count sequence to include multiple hundreds and end their sequence at 1,000 (2.NBT.A.2). This is pivotal to students' number sense formation as students cannot reliably add and subtract to numbers they have not counted. In this topic, students also locate numbers on a number line and use a number line as a tool to compare and order threedigit numbers. Students were introduced to number lines in Unit 3 with their work with measurement and adding and subtracting within 100. This is the first time they will see the number line extended beyond 100, to 1,000. Beyond the number line, students also use their place value knowledge to compare and order threedigit numbers by reasoning about the number of hundreds, tens, and ones in each number (2.NBT.A.4).
Finally, in Topic C students see place value in action with their work with money and coins. They focus on identifying coins and their value in order to find the value of coin collections. Using their knowledge that 10 tens make a hundred, students see that their work with dimes is similar as 10 dimes makes 100 cents, or a new unit, a dollar. Students' work with money primarily stays within a dollar; they reason how to make a dollar or get change from a dollar. This reinforces student work of adding and subtracting within a 100 from Unit 2. In working with coins, students also continue to work on skipcounting as they count coin groupings flexibly by 10s, 5s, and 1s (2.NBT.A.2). Students continue their application of their work with money as they solve onestep and twostep word problems involving money situations (2.MD.C.8). The end of the unit continues their gradelevel work with twostep word problems as they explore combining add to and take from change unknown problem types, considered to be middle difficulty subtypes with easier results unknown subtypes (2.OA.A.1). By the end of Grade 2, students should be proficient in these types of twostep word problem combinations with addition and subtraction.
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The following assessments accompany Unit 4.
Have students complete the MidUnit Assessment .
Use the resources below to assess student understanding of the unit content and action plan for future units.
concrete base ten blocks 
134 shown in base ten blocks


pictorial base ten blocks 
Example: Represent 342 with base ten block drawing.


place value chart 


number line 

coin models 


tape diagram 
Example: Armando buys 16 peppers for a barbecue. 7 of the peppers are red and the rest of the peppers are orange. How many orange peppers did Armando buy?

compare
dime
equal =
estimate
expanded form
greater than >
less than <
nickel
penny
quarter
standard form
unit form
word form
To see all the vocabulary for Unit 4 , view our 2nd Grade Vocabulary Glossary.
Base ten blocks (9 hundred, 20 tens, 20 ones per student or small group of students)
Optional: Paper base ten blocks (hundreds, tens, ones) (9 hundred, 20 tens, 20 ones per student or small group of students) — If regular base ten blocks are not available students can use paper versions
Hundreds place value chart (1 per student)
Blank Hundreds Chart (10 per group) — Can be used again in Unit 5 as a resource
Tape or Glue stick (1 per group) — To attach sets of hundreds charts together vertically
Optional: Set of Coins (Teacher set) — Penny, nickel, dime, quarter
Optional: Visual of a Dollar (Teacher set)
Topic A: Understanding and Representing Three Digit Numbers
Topic B: Reasoning with Numbers to 1000
Topic C: Place Value in Action  Money and Word Problems
Key
Major Cluster
Supporting Cluster
Additional Cluster
CCSS.MATH.PRACTICE.MP1 — Make sense of problems and persevere in solving them.
CCSS.MATH.PRACTICE.MP2 — Reason abstractly and quantitatively.
CCSS.MATH.PRACTICE.MP3 — Construct viable arguments and critique the reasoning of others.
CCSS.MATH.PRACTICE.MP4 — Model with mathematics.
CCSS.MATH.PRACTICE.MP5 — Use appropriate tools strategically.
CCSS.MATH.PRACTICE.MP6 — Attend to precision.
CCSS.MATH.PRACTICE.MP7 — Look for and make use of structure.
CCSS.MATH.PRACTICE.MP8 — Look for and express regularity in repeated reasoning.
Unit 3
Measurement
Unit 5
Adding and Subtracting Within 1,000
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