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Grade 6 Mathematics Module 2, Topic B: Multi-Digit Decimal Operations--Adding, Subtracting, and Multiplying

Classroom Resource Information

Title:

Grade 6 Mathematics Module 2, Topic B: Multi-Digit Decimal Operations--Adding, Subtracting, and Multiplying

URL:

https://www.engageny.org/resource/grade-6-mathematics-module-2-topic-b-overview

Content Source:

EngageNY

Type:

Lesson/Unit Plan

Overview:

Prior to the division of decimals, students will revisit all decimal operations in Module 2, Topic B. Students have had extensive experience of decimal operations to the hundredths and thousandths (5.NBT.7), which prepares them to easily compute with more decimal places. Students begin by relating the first lesson in this topic to mixed numbers from the last lesson in Topic A. They find that sums and differences of large mixed numbers can sometimes be more efficiently determined by first converting the number to a decimal and then applying the standard algorithms (6.NS.3). They use estimation to justify their answers.

Within decimal multiplication, students begin to practice the distributive property. Students use arrays and partial products to understand and apply the distributive property as they solve multiplication problems involving decimals. By gaining fluency in the distributive property throughout this module and the next, students will be proficient in applying the distributive property in Module 4 (6.EE.3). Estimation and place value enable students to determine the placement of the decimal point in products and recognize that the size of a product is relative to each factor. Students learn to use connections between fraction multiplication and decimal multiplication.

Content Standard(s):

Mathematics
MA2019 (2019)
Grade: 6

6. Add, subtract, multiply, and divide decimals using a standard algorithm.

Unpacked Content

Evidence Of Student Attainment:

Students:
Given a context which calls for complex computation involving multi-digit decimals,

Choose the most appropriate strategy for computing the answer.
Produce accurate results efficiently using a standard algorithm for each operation when appropriate.

Teacher Vocabulary:

Standard algorithms (addition, subtraction, multiplication, and division)
Quotient
Sum
Product
Difference
Tenths
Hundredths
Thousandths
Ten thousandths
Hundred thousandths

Knowledge:

Students know:

Place value conventions (i.e., a digit in one place represents 10 times as much as it would represent in the place to its right and 1/10 of what it represents in the place to its left).
Strategies for computing answers to complex addition, subtraction, multiplication, and division problems involving multi-digit decimals, including a standard algorithm for each operation.

Skills:

Students are able to:

Strategically choose and apply appropriate computation strategies.
Accurately find sums, differences, products, and quotients using the standard algorithms for each operation.

Understanding:

Students understand that:

Place value patterns and values continue to the right of the decimal point and allow the standard algorithm for addition and subtraction to be applied in the same manner as with whole numbers.
Mathematical problems can be solved using a variety of strategies, models, and representations.
Efficient application of computation strategies is based on the numbers and operations in the problem.
The steps used in the standard algorithms for the four operations can be justified by using properties of operations and understanding of place value.
Among all techniques and algorithms that may be chosen for accurately performing multi-digit computations, some procedures have been chosen with which all should be fluent for efficiency, communication, and use in other mathematics situations.

Diverse Learning Needs:

Essential Skills:

Learning Objectives:
M.6.6.1: Solve division problems involving multi-digit whole numbers and decimal numbers with or without a calculator.
M.6.6.2: Solve multiplication problems involving multi-digit whole numbers and decimal numbers with or without a calculator.
M.6.6.3: Recall basic multiplication and division facts.
M.6.6.4: Solve addition and subtraction of multi-digit decimal numbers (emphasis on alignment).
M.6.6.5: Solve addition and subtraction of multi-digit whole numbers.
M.6.6.6: Recognize place value of whole numbers and decimals.
M.6.6.7: Demonstrate addition, subtraction, multiplication, and division of whole numbers and decimals using manipulatives.

Prior Knowledge Skills:

Recall basic multiplication facts.
Recall basic addition, subtraction, multiplication, and division facts.
Use place value understanding to round whole numbers to the nearest 10 or 100.
Identify place value of decimals to the tenths and hundredths.
Recall basic addition and subtraction facts.
Recall basic addition and subtraction facts.
Recall basic addition, subtraction, and multiplication facts.
Multiply within 100, using strategies such as the relationship between multiplication and division.
Multiply within 100, using strategies such as properties of operations.
Divide within 100, using strategies such as properties of operations.
Divide within 100, using strategies such as the relationship between multiplication and division.
Add and subtract within 1000.

Alabama Alternate Achievement Standards

AAS Standard:
M.AAS.6.6 Solve two-factor multiplication problems with products up to 100 (whole numbers only).

Tags:

add, algorithm, decimals, divide, multidigit, multiply, subtract

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Accessibility

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Comments

There are three lessons in this topic.

This resource is free for teachers to access and use. All resources required for the lessons are available to print from the site.

This resource provided by:

Author:

Hannah Bradley

ALEX Classroom Resource

Grade 6 Mathematics Module 2, Topic B: Multi-Digit Decimal Operations--Adding, Subtracting, and Multiplying