Students are introduced to multidigit multiplication and its applications, including multiplicative comparison.
Math
Unit 2
4th Grade
In Unit 2, 4th grade students multiply up to fourdigit numbers by onedigit numbers, relying on their understanding of place value and properties of operations, as well as visual models like an area model, to solve.
As a foundation for their multiyear work with multiplication and division, students in 2nd grade learned to partition a rectangle into rows and columns and write a repeated addition sentence to determine the total. They also skipcounted by 5s, 10s, and 100s. Then, in 3rd grade, students developed a conceptual understanding of multiplication and division in relation to equal groups, arrays, and area. They developed a variety of strategies to build toward fluency with multiplication and division within 100 and applied that knowledge to the context of one and twostep problems using the four operations.
To begin the unit, students extend their understanding of multiplication situations that they learned in 3rd grade to include multiplicative comparison using the words “times as many.” This helps acquaint students with these types of problems before solving them with larger quantities later in the unit. It also gives students time to refresh their multiplication and division facts from 3rd grade, since the problems in Topic A are limited to those that involve multiplication and division within 100. Then, students move into twodigit by onedigit, threedigit by onedigit, fourdigit by onedigit, and twodigit by twodigit multiplication, using the area model, partial products, and finally the standard algorithm, making connections between all methods as they go. The use of the area model serves to help students conceptually understand multiplication and as a connection to their work with area and perimeter (4.MD.3), a supporting cluster standard. Finally, with a full understanding of all multiplication cases, they then apply their new multiplication skills to solve multistep word problems using multiplication, addition, and subtraction, including cases involving multiplicative comparison (4.NBT.5, 4.OA.3, 4.MD.3), allowing for many opportunities to connect content across multiple domains.
This unit affords lots of opportunities to deepen students’ mathematical practices. For example, “when students decompose numbers into sums of multiples of baseten units to multiply them, they are seeing and making use of structure (MP.7). Further, “by reasoning repeatedly (MP.8) about the connection between math drawings and written numerical work, students can come to see multiplication and division algorithms as abbreviations or summaries of their reasoning about quantities” (NBT Progression, p. 14). Lastly, as students solve multistep word problems involving addition, subtraction, and multiplication, they are modeling with mathematics (MP.4).
Students’ work in this unit will prepare them for fluency with the multiplication algorithm in 5th grade (5.NBT.5). Students also learn about new applications of multiplication in future grades, including scaling quantities up and down in 5th grade (5.NF.5), all the way up to rates and slopes in the middle grades (6.RP, 7.RP). Every subsequent grade level depends on the understanding of multiplication and its algorithm, making this unit an important one for students in 4th grade.
Pacing: 21 instructional days (18 lessons, 2 flex days, 1 assessment day)
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The following assessments accompany Unit 2.
Have students complete the PreUnit Assessment and PreUnit Student SelfAssessment before starting the unit. Use the PreUnit Assessment Analysis Guide to identify gaps in foundational understanding and map out a plan for learning acceleration throughout the unit.
Have students complete the MidUnit Assessment after lesson 10.
Use the resources below to assess student understanding of the unit content and action plan for future units.
Before you teach this unit, unpack the standards, big ideas, and connections to prior and future content through our guided intellectual preparation process. Each Unit Launch includes a series of short videos, targeted readings, and opportunities for action planning to ensure you're prepared to support every student.
Models for up to 4digit by 1digit multiplication 
Written Numerical Work 
base ten block array (remedial  can be concrete or pictorial)

horizontally written partial products 
graph paper array (remedial)

partial product algorithm with decreasing partial products 
area model

partial product algorithm with increasing partial products 

standard algorithm 
Models for up to 2digit by 2digit Multiplication 
Written Numerical Work 
base ten block array (remedial  can be concrete or pictorial)

horizontally written partial products 
graph paper array (remedial)

partial product algorithm with decreasing partial products 
area model

partial product algorithm with increasing partial products 

standard algorithm 
partial product
To see all the vocabulary for Unit 2, view our 4th Grade Vocabulary Glossary.
Topic A: Multiplicative Comparison
Topic B: Multiplication of up to FourDigit Whole Numbers by OneDigit Whole Numbers
Topic C: Multiplication of TwoDigit Whole Numbers by TwoDigit Whole Numbers
Topic D: MultiStep 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 1
Place Value, Rounding, Addition, and Subtraction
Unit 3
MultiDigit Division
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